cds composite design & simulation software v3nwp.engr.udel.edu/ccm/cds/cds3.0-help.pdfcurrent...

CDSComposite Design &

Simulation Software v3.0

Help Documentation v3.0 October 2010

© Center for Composite MaterialsUniversity of Delaware 2010

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© University of Delaware, Center for Composite Materials, 2008

CDS Help Documentation

Table of Contents

Welcome to CDS 4 Introduction 4 What's New! 6 History of CDS 8 Screenshots of CDS3.0 9Installation 11 Downloading CDS 11 Installation 12 Supported OS 14 Installation of CDS3.0 license 15CDS Versions 17 Version Overview 17 Demo Version 18 Academic Version 19 Standard Version 20 Professional Version 21Using CDS3.0 22 CDS Input and Output 23 The Menu Tree 24 Overview of the Menu Tree 24 Experiments 25 Materials 26 Laminas 28 Adding to Materials 29 Laminates 31 Analysis 32 Thermal Analysis 34 1D Transient Conduction in a Cylinder 35 Moisture Analysis 36 1D Moisture Diffusion 37 Structural Analysis 38 Thick Plate Model 39 Plane Strain Cylinder Model 40 Discontinuous Tile Model 41 Compliant Interlater Model 42 Thin Plate Impact Model 43 Sources 44 Loading and Saving Data 45 Loading Experiments 45 Loading Data into CDS 46 Saving Data 48 Exporting Data 49 The Input Section 50 Experiments 50 Materials Input 52 Lamina 53 Stacking 54 Loading 55 Info 56 The Results Section 57

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Materials Summary 57 Micromechanics 58 Properties 59 Processing-Thermal 60 Response 61Theory 62 Thermal Models 63 Transient Condiction in Thick Walled Cylinder 63 Moisture Theory 64 Moisture Diffusion Theory 64 Structural Mechanics Theories 65 Thin Plate (Classical Laminate) Model 65 Thick Plate Model (Plane Strain) Theory 71 Plain strain Cylinder Theory 74Legal 88 Disclosure 88

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Welcome to CDS

Introduction

CDS3.0 : Composite Design andSimulation Environment is an advancedsoftware application for designing andanalyzing composite structures. With thissoftware, an designer engineer, processengineer or student can quickly determinethe effective properties of compositelaminates, conduct micromechanicscalculations, as well as virtual processsimulation and optimization.

This software provides built in usermaterials database functionality, FEAexport and has a number of uniquemodules for structural mechanicssimulations. A menu tree environment isused to quickly sore and retrieve datagenerated within the software, importedfrom raw data or exported to common FEAinput formats.

This help menu is provided to aid the userin quickly getting started as well asprovide detailed information ongenerating and optimizing virtuallaminates, conducting progressive failureand exported data for subsequent analysis

Click on any help topic to the left to learnmore.

You can also open the context menu andhover over any object on the main screento learn about its functionality.

If you have any questions, contact Dr.John J. Tierney at the Center forComposite Materials, University ofDelaware

© 2010 Center for Composite Materials,University of Delaware, Newark DE 19716

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What's New in CDS 3.0The University of Delaware's Center for Composite Materials, (CCM) has been creating

design and analysis software for composite structures for more than two decades. The newestrelease of this software, called CDS3.0, builds upon previous versions with integrated parametricdesign and analysis of composite laminates and cylinders, material ranking, drag-and-dropfunctionality with standard spreadsheet import and export. The software consolidates CCM’scurrent composite solid mechanics applications into a single environment that conducts effectiveproperty predictions, plate and cylinder analysis with integrated material property management,as well as thermal and process simulation, all with real-time results.

At the heart of this environment is a new materials database structure that captures all ofthe features of the original database software while adding such new attributes as materialtracking, property locking features, and real-time design. The materials database tree also allowscreation of sub-databases that can be used to store fiber and matrix properties. Users can createand manipulate material databases that store a wide range of material information. Each materialcurrently stores 170 material property values, each of which also contains source, date, and unitinformation. Properties include mechanical and physical properties, micromechanics parameters,cure kinetics, and damage and failure properties, as well as non-linear and MAT162 (LS-DYNA)properties. A custom units section is also available for users to add their own material fields. Theuser can modify properties “on the fly” and see laminate effective properties, stresses, strains,and progressive failure in real time. Material property sources and units are tracked to ensurevalidity during analysis and can be exported to third-party FEA packages for further design andanalysis.

Micromechanics calculations include continuous laminas, SMC, particulate reinforcement,random mat and short fiber composites. The next release of the software slated this summer willalso incorporate fabric micromechanics. Lamina properties are generated in real time and can beused in laminate structural design and optimization allowing the user to try various materials, varyfiber volume fraction or architecture.

The laminate workbench in the new environment has been greatly improved and allowseasy creation of sub-laminates within laminates. Users can quickly create and manipulate up to100 unique laminates while generating real-time effective properties and resulting stresses,strains, and displacements as well as progressive failure by simply clicking on each laminateduring an analysis. This allows easy comparison and ranking of materials for down-selection indesign.

The analysis environment allows users to virtually apply thermal, mechanical or moistureloading and observe laminate response. This environment also allows incorporation of additionalmodules such as discontinuous sandwich analysis and laminates with compliant interlayers. Theglobal load vectors are dependent on the type of structure under investigation, and all resultsfrom loading are displayed in real time. Progressive failure tables identify the failure ply, modeand load at failure for a number of common failure theories.

Material property source information is as important to the analysis as the property dataitself and is can be applied to every value of every material in all databases. Source 'templates'can also be used to quickly assign source information to property data sets and date stamping isalso available.

The CDS Suite is available to industrial consortium members through consortiumagreements tailored to program requirements and duration of contracts. CCM researchers willwork in parallel with consortium members with the design and analysis phase so that memberslearn to successfully use this software independently on current or future projects. Demonstrationversions of the CDS suite will be made available to potential members with training workshops atCCM or online through web meetings. An online comprehensive guide and software support willalso be made available to allow consortium members to use CDS both independently and to

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encourage future partnerships on new projects.

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History of CDS

CCM has been creating design and analysis software for compositestructures for more than two decades. The newest release of this software, calledCDS3.0, builds upon previous versions with integrated parametric design andanalysis of composite laminates and cylinders, material ranking, drag-and-dropfunctionality with standard spreadsheet import and export. The softwareconsolidates CCM’s current composite solid mechanics applications into a singleenvironment that conducts effective property predictions, plate and cylinderanalysis with integrated material property management, as well as thermal andprocess simulation, all with real-time results.

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Screenshots of CDS3.0

Transient analysis of Composite Cylinder in CDS3.0

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Biaxial Loading of Thin Section Composite Laminate

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Installation

Download CDS

This zip file contains all modules available within the CDSenvironment which include Academic, Standard, Professionalbased features. The appropriate module is activated basedon the key requested.

A single download is all that's required to install and run thesoftware on the client PC. Unlike previous versions of CDS,the LabVIEW runtime engine is installed directly within theCDS install and no other additional installer is necessary toactivate or use the software.

Once you download the CDS application, double click the zipfile to unzip into any folder on the client PC. Check the website often to ensure you are running the latestversion on your client PC. Then proceed to Installation Instructions.

2010 Center for Composite Materials, University ofDelaware, Newark DE 19716

Download Link:

CDS_version3.0aRelease 10-2010

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http://www.ccm.udel.edu/CDS/CDS3.0.zip



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Installation

To install the CDS software, you first need to unzipthe file downloaded from the CCM website to a folderon your PC. Double click the zip file to initiate the unzippingprocess. You can use the windows default "extract"option or other unzip utility such as WinZIP to extractthe files.

To use the built in windows extraction tool. Select theCDS zip file, right click and select "Extract All". Youcan extract the file to any location on your PC forinstallation. It is recommended that you create afolder during this process and place it in a locationwhere you typically store installation files.

Once the files are unzipped, open the folder thatcontains the unzipped files and double click the"setup.exe" file to begin installation of CDS2.0 onyour PC. The following screen should appearindicating initiation of the installation process. ClickNext to continue, or cancel to quit the installationprocess.

The next screen will ask for destination directories.The default location is C:\Program Files\ and it isrecommended that you install the application to thislocation. Additional National Instruments productsinclude the LabVIEW runtime engine v8.6 which isrequired for the software to run.

Once you've selected the appropriate folder and hitnext, you will then have to agree with two licenseagreements, one pertaining to the CDS releasefollowed by a National Instruments licenseagreement. If you agree to these licenses thensoftware will then install on you system.

If you have already installed CDS on your PC the newinstallation will update the previous version. There isno need to reinstall a license key if you have alreadydone so in the past.


Figure 1. CDS InstallationOpening Screen

Figure 2. CDS InstallationDestination Directory Screen

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Supported Operating Systems

The CDS software runs on Intel based PC's running the Windows XP,Windows Vista and Windows 7 operating system.

PC requirements 128MB RAM, Windows x32 and x64 bit versions ofWindows NT, Windows XP, Windows Vista and Windows 7.

A minimum screen resolution of 1024x768 pixels is required to view the fullCDS3.0 environment.

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Installation of CDS3.0 license

To install a full license of CDS3.0 you have to carry out thefollowing steps.

1. Download CDS from the download page

2. Unzip the file to a folder of your choosing and run thesetup.exe file.

3. Follow previous instructions to install the software.Installation of CDS3.0 on a previous 3.0 installation willupdate the old version.

4. Run the software. If you do not already have a keyinstalled click in the "Request Key" button.

5. Fill out the form below and click the "save to file" button. 6. Email the generated file to [email protected]. A key fileis created for your specific computer and will be emailedback to you.

7. Start CDS3.0 and click the "Import Key" button. Selectthe .key file that was emailed to you.

8. The software will now work and you can click the "Start"key to use it. Based on the license granted, specific featuresof CDS3.0 will be unlocked and ready for use. The CDS3.0 key files will eventually expire so if you are avalid user you may request a new key.

You can email [email protected] for a replacement key filewith a new expiration date.

You can determine what features are unlocked in the CDSversions section


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CDS Versions

Version Overview

Modules available within the CDS software are based on the versionrelease shown below. Users are typically given access to thestandard release but may also be allowed access to the professionalrelease if involved with projects with UD-CCM.


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Demo Version

The demo version is installed by default and is preloaded with examplematerials for the user to try out in simple design and analysis studies. Thisversion is limited to viewing materials and has limited laminate editingcapabilities

Once a valid key is imported the software switches from "demo" mode andfeatures allowed for that particular key are unlocked.

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Academic Version

The academic version allows full material control, allows design and analysis ofthin section composites and the user can load and save the analysis. Some heat transfer modules are also unlocked with this version depending on theproject or relationship with the academic institution.


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Standard Version

CDS2.0 Standard version is the most common release of the software and isthe version released to UD-CCM industrial consortium members, someacademic institutions and government researchers.


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Professional Version

CDS2.0 Professional is released to all UD-CCM researchers and sponsoringgovernment agencies. All modules including specialized solid mechanics codesare made available to those agencies to conduct research in composites. UD-CCMresearchers work closely with those agencies in developing new features andcodes relating to new materials, and models as they are developed with ongoingresearch.

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Using CDS3.0

CDS Input and Output

The CDS environment is a single window GUI(Graphical User Interface) with real time designand analysis functionality. The GUI is dividedinto three sections: The left section contains amenu tree where all data input and generatedoutput is stored. Right clicking any entity inthe menu tree will invoke a series of operationsrelated to the entity selected. The top right section is where the user entersinformation and the bottom right section tabwhere results are displayed.

A breakdown of the inputs in each section aredescribed below

Common Menu-tree Right Click optionso Load-Save: Section used to load

and save any information stored orcreated in CDS2

o New-Duplicate: A new or duplicateentity can be created. Multipleentities can be duplicated byselecting existing entities whileholding the shift or control key

o Add to Materials: Materialproperties generated within laminasor laminates can be added to thematerial database. Multiple entitiescan be added by selecting existingentities while holding the shift orcontrol key

o Analysis: Currently three analysistypes exist, thermal, moisture andstructural. A number of solvers areavailable for each analysis type.Data generated in one analysis canbe used as an input for a relatedanalysis.

o Options: Specific options forhandling and viewing data is set inthis section.

Input Sectiono Experiments: Coming soon will be

the option to import rawexperimental data for reduction tomaterial properties

o Materials: Enter and modifymaterial properties in this section.

o Lamina: Create laminas frommaterials in this section.

o Stacking: This section is where

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laminates are created and stored.o Loading: Inputs for all analysis

conditions are entered in thissection.

o Info: Use this section to storeinformation used in other areas ofCDS2.0.

Resultso Materials Summary: Graphical

summary of materials stored inCDS2.0

o Micromechanics: Results frommicromechanics simulations

o Properties: Results from Laminatesimulations

o Processing-Thermal: Results fromProcess and Thermal ModelingSimulations

o Response: Stress, Strain,Displacement and factors of safetyresults

Click on each section above to learn more.

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The Menu Tree

Overview of the Menu Tree

The menu tree is where all user data is created,loaded and saved. Right clicking on any existingentity will bring up a series of options such as new,load, save, export etc. The right click menu adaptsto the selection clicked.

The user can click on one or more entities whichwill also change the right click options available.For example right clicking on a list of materials(selected with the shift key) and selecting theduplicate function will duplicate these materials.Right clicking on the Materials entry will duplicatethe entire set of materials.

This functionality is common throughout theCDS3.0 menu environment allowing rapid creationof materials, laminas, laminates etc.

You can select multiple items in a row by holdingthe shift key or discrete items with the control keypressed when selecting items. Note that you canonly multi select items on the same level and submenu.

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Experiments

The Experiments menu tree item is currently undergoing testing and will be available in thenear future. This section will allow import of raw experimental data files to determine material propertiesthat can then be used in a composite analysis.

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Materials

All material data is stored in under theMaterials menu tree. By default 87 materialsare loaded into CDS3.0 as example materials.These materials range in form from fibers,matrices (isotropic) and laminas to laminates,dry fabrics, liquids and gases. The properassignment of the material type is importantwhen exporting data to an FEA format forsubsequent analysis.

Right click functions:

New Material: Creates a new blank materialat the end of the database. Rename: renames the selected materialChange material type: Available typesinclude fibers, matrices (isotropic) and laminasto laminates, dry fabrics, liquids and gases.You can change one or more materials byholding the shift or control key. The menu iconwill change to reflect the changed materialtype. Duplicate Material: Duplicates the selectedmaterial or materials. If the Materials menutree is right clicked, all materials areduplicated. All duplicated materials will berenamed with a "copy" prefix to identify themas a copy of an existing material and notconfuse the user with a material may bealready be used in a laminate or analysisDelete Material(s): Deletes the selectedmaterials

Load: Splits the window into two sections andopens a dialog box. Open a previously savedfile and the data from that fill will be loadedinto the top section. The user can then selectany or all items and load them into the currentenvironment. Save Selected: Saves the selected item to aspreadsheet file. The created file is tabdelimited and can be opened in notepad orMicrosoft Excel. If the file is saved with a *.xlsextension then the file will be loaded intoMicrosoft Excel by default. Export: Depending on the selected entity thedata may be exported in a format that can bethen read into a commercial FEA environmentsuch as Abaqus or Ansys.

Depending on what section is right clickedsome or all of the above options are disabled.These items are also disabled if the user doesnot have the appropriate license file installed.Demonstration mode greatly limits what rightclick functions are available.

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Laminas

Laminas represent a single ply and is comprised of a seriesof constituent materials and architecture. The user firstcreates a lamina to populate the database with an entry.The materials and microstructure are then selected andproperties are then generated automatically.


New lamina: Creates a new blank lamina at the end of thedatabase. The lamina input table is also populated with anew row that requires selection of the appropriate materialsneeded to create a lamina. Rename: renames the selected lamina Duplicate lamina: Duplicates the selected lamina orlaminas. If the laminas menu tree is right clicked, alllaminas are duplicated. All duplicated laminas are renamedwith a "copy" prefix to identify them as a copy of an existinglamina and not confuse the user with another lamina may beused in a laminate or analysisAdd Lamina to Materials: Adds the selected lamina orlaminas to the materials library. The new materials will bepopulated with all properties generated by the laminaanalysis. All other properties not generated within CDS3.0are given a value of zero. Delete Lamina(s): Deletes the selected lamina or laminas

Load: Splits the window into two sections and opens adialog box. Open a previously saved file and the data fromthat fill will be loaded into the top section. The user can thenselect any or all items and load them into the currentenvironment. Save Selected: Saves the selected item to a spreadsheetfile. The created file is tab delimited and can be opened innotepad or Microsoft Excel. If the file is saved with a *.xlsextension then the file will be loaded into Microsoft Excel bydefault. Export: Depending on the selected entity the data may beexported in a format that can be then read into acommercial FEA environment such as Abaqus or Ansys.

Depending on what section is right clicked some or all of theabove options are disabled. These items are also disabled ifthe user does not have the appropriate license file installed.Demonstration mode greatly limits what right click functionsare available.

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Adding to MaterialsThe "Add Lamina to Materials" Adds the selected lamina or laminas to the materials library.The new materials will be populated with all properties generated by the lamina analysis. Allother properties not generated within CDS3.0 are given a value of zero.

The lamina is populated with material data from the materials library including thearchitecture which is applied to the parameters column in the lamina input area. Once the "Add Lamina to Materials" right click option is selected, the created properties are added toa new material and is then available to save or export. Created lamina data is not saved untilthis function is selected.

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Laminates

A laminate is a material that can beconstructed by uniting two or more layers ofmaterial together. The process of creating alaminate is lamination, which in commonparlance refers to the placing of somethingbetween layers of plastic and gluing them withheat and/or pressure, usually with anadhesive.

Layers of different materials may be used,resulting in a hybrid laminate. The individuallayers generally are orthotropic (that is, withprincipal properties in orthogonal directions) ortransversely isotropic (with isotropic propertiesin the transverse plane) with the laminate thenexhibiting anisotropic (with variable directionof principal properties), orthotropic, orquasi-isotropic properties. Quasi-isotropiclaminates exhibit isotropic (that is,independent of direction) inplane response butare not restricted to isotropic out-of-plane(bending) response. Depending upon thestacking sequence of the individual layers, thelaminate may exhibit coupling between inplaneand out-of-plane response. An example ofbending-stretching coupling is the presence ofcurvature developing as a result of inplaneloading.


New laminate: Creates a new blank laminateat the end of the database. Rename: renames the selected laminateDuplicate lamina: Duplicates the selectedlaminate or laminates. If the laminates menutree is right clicked, all laminates areduplicated. All duplicated laminates arerenamed with a "copy" prefix to identify themas a copy of an existing laminate and notconfuse the user with another laminate may beused in an analysisAdd Laminate to Materials: Adds theselected laminate or laminates predictedproperties to the materials library. The newmaterials will be populated with all propertiesgenerated by the laminate analysis. All otherproperties not generated within CDS3.0 aregiven a value of zero.

Delete Laminate(s): Deletes the selectedlaminate or laminates

Load: Splits the window into two sections andopens a dialog box. Open a previously savedfile and the data from that fill will be loaded

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into the top section. The user can then selectany or all items and load them into the currentenvironment. Save Selected: Saves the selected item to aspreadsheet file. The created file is tabdelimited and can be opened in notepad orMicrosoft Excel. If the file is saved with a *.xlsextension then the file will be loaded intoMicrosoft Excel by default. Export: Depending on the selected entity thedata may be exported in a format that can bethen read into a commercial FEA environmentsuch as Abaqus or Ansys.

Depending on what section is right clickedsome or all of the above options are disabled.These items are also disabled if the user doesnot have the appropriate license file installed.Demonstration mode greatly limits what rightclick functions are available.

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Analysis

The analysis tree menu input is where the user creates either athermal simulation, moisture analysis or structural analysis.

A number of different analyses exist for each section, forexample a thermal analysis can be a 1D steady state analysisor a 1D transient analysis of a cylinder structure.

Currently a moisture analysis is limited to 1D absorption ordesorption of water in a heterogeneous media.

In a structural analysis the user can example a thin section orthick section laminate, a thick section cylinder or studyproblems such as a laminate with a compliant interlayer, adiscontinuous tile array or an impact problem on a thin platestrucuture. In some instances the analyses can be coupled, forexample the results of a transient thermal analysis on acylinder can be transferred to a stress analysis for the samecylinder. The transient thermal analysis results can beoverlayed on the results of processing and loading the cylinder,thus giving a true measure of stresses and strains within thecylinder during it's lifetime.

Click on the various sections to learn more about the analysisoptions available in CDS3


New: Creates a new analysis, thermal, moisture or structural. Rename: renames the selected analysisDuplicate Analysis: Duplicates the selected analysis oranalyses. If the analysis menu tree is right clicked, all analysesare duplicated. All duplicated analyses are renamed with a"copy" prefix to identify them as a copy of an existing analysisand not confuse the user with another analysis. This alsoapplied to a thermal, moisture or structural subtree. Delete Analysis: Deletes the selected analysis

Load: Splits the window into two sections and opens a dialogbox. Open a previously saved file and the data from that fillwill be loaded into the top section. The user can then selectany or all items and load them into the current environment.

Save Selected: Saves the selected item to a spreadsheet file.The created file is tab delimited and can be opened in notepador Microsoft Excel. If the file is saved with a *.xls extensionthen the file will be loaded into Microsoft Excel by default. Export: Depending on the selected entity the data may beexported in a format that can be then read into a commercialFEA environment such as Abaqus or Ansys.

Depending on what section is right clicked some or all of theabove options are disabled. These items are also disabled if theuser does not have the appropriate license file installed.Demonstration mode greatly limits what right click functionsare available.

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Thermal Analysis

Currently the thermal analysis options are limited to 1D steady stateanalysis of thick section composites and 1D transient analysis ofcomposite cylinder structures.

To create an analysis of simply right click the analysis or thermal subtree and select New:Thermal: and then select the analysis you wish tocreate. The top right input section will then allow you to fill out theprocess or operating temperature input conditions.

Right Click Functions

New: Thermal Creates a new thermal analysis. Rename: renames the selected analysisDuplicate Analysis: Duplicates the selected analysis or analyses. Ifthe analysis menu tree is right clicked, all analyses are duplicated. Allduplicated analyses are renamed with a "copy" prefix to identify themas a copy of an existing analysis and not confuse the user with anotheranalysis. This also applied to a thermal, moisture or structuralsubtree. Delete Analysis: Deletes the selected analysis

Load: Splits the window into two sections and opens a dialog box.Open a previously saved file and the data from that fill will be loadedinto the top section. The user can then select any or all items and loadthem into the current environment.

Save Selected: Saves the selected item to a spreadsheet file. Thecreated file is tab delimited and can be opened in notepad or Microsoft Excel. If the file is saved with a *.xls extension then the file will beloaded into Microsoft Excel by default.

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1D Transient Conduction in a Cylinder

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Moisture Analysis

The moisture analysis input section iscurrently not active in CDS3.0 but will bemade available in the near future.

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1D Moisture Diffusion

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Structural Analysis

Currently the structural analysis options are thin and thick laminateanalysis, thick walled cylinder, compliant interlayer, discontinuous tilemodel and thin plate impact. More structural modules will be added inthe near future.

To create an analysis of simply right click the analysis or structural subtree and select New:Structural: and then select the analysis you wishto create. The top right input section will then allow you to fill out theprocess or operating temperature input conditions.

Right Click Functions

New: Thermal Creates a new thermal analysis. Rename: renames the selected analysisDuplicate Analysis: Duplicates the selected analysis or analyses. Ifthe analysis menu tree is right clicked, all analyses are duplicated. Allduplicated analyses are renamed with a "copy" prefix to identify themas a copy of an existing analysis and not confuse the user with anotheranalysis. This also applied to a thermal, moisture or structural subtree. Delete Analysis: Deletes the selected analysis

Load: Splits the window into two sections and opens a dialog box.Open a previously saved file and the data from that fill will be loadedinto the top section. The user can then select any or all items and loadthem into the current environment.

Save Selected: Saves the selected item to a spreadsheet file. Thecreated file is tab delimited and can be opened in notepad or Microsoft Excel. If the file is saved with a *.xls extension then the file will beloaded into Microsoft Excel by default.

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Thick Plate Model

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Plane Strain Cylinder Model

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Discontinuous Tile Model

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Compliant Interlater Model

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Thin Plate Impact Model

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Sources

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Loading and Saving Data

Loading Experiments

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Loading Data

The Load button a file into CDS2.0. Once an excel spreadsheet is loaded the left list ispopulated with all the information in the file. The user can then select some or all of thisinformation in memory. An example of a loaded set of data is shown below where a series oflaminates are loaded from a Microsoft Excel Spreadsheet into CDS2 These laminates werecreated in CDS2 and reloaded back into CDS2 for analysis.

The spreadsheet format for the file loaded in the above case is shown below. The spreadsheetis comprised of a summary sheet (sheet 1) followed by a sheet containing a series oflaminates. In this case 22 laminates were created and are shown

The load save Tab is where input and results can be loaded from and saved to specific fileformats. The file format commonly used by CDS is Microsoft Excel Spreadsheet format.(*.xlsx). The

Other file save options are available but the spreadsheet option is best as these files can bereopened back into CDS2.0. This commonly used format is format specific in that the layoutof the spreadsheet should not be changed so that the files can be loaded back into CDS2.0 ata later time. The user can edit the properties within the database within Microsoft Excel andreload these files into CDS2.0.

CDS Load Save Interface

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There are four buttons in the load-save tab. Clic k on each link for more detailed inormation. Asummery of each button is shown here. Load: Loads a file into CDS2.0. Once an excel spreadsheet is loaded the left list is

populated with all the information in the file. The user can then select some or all of thisinformation in memory.

Select: Selects loaded information and imports it directly into CDS2. If informationmatches data already within CDS2 then a "-copy" is attached to the data and is loaded.

Clear: Clears all imported data from memory. Save: Saves CDS2 information to a file based on the drop down selection. The default CDS

Standard file is an Microsoft Excel spreadsheet.

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Saving Data


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Exporting Data

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The Input Section

Experiments

TheExperimentsmenutreeitem iscurrentlyundergoingtestingandwill beavailable inthenearfuture. Thissection willallowimportof rawexperimental datafiles todeterminematerialpropertiesthatcanthenbeusedin acompositeanalysis.

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Experiments input window is currently blank and under development

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Materials Input

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Lamina

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Stacking

A laminate is a material that can beconstructed by uniting two or more layers ofmaterial together. The process of creating alaminate is lamination, which in commonparlance refers to the placing of somethingbetween layers of plastic and gluing themwith heat and/or pressure, usually with anadhesive.

Layers of different materials may be used,resulting in a hybrid laminate. The individuallayers generally are orthotropic (that is, withprincipal properties in orthogonal directions)or transversely isotropic (with isotropicproperties in the transverse plane) with thelaminate then exhibiting anisotropic (withvariable direction of principal properties),orthotropic, or quasi-isotropic properties.Quasi-isotropic laminates exhibit isotropic(that is, independent of direction) inplaneresponse but are not restricted to isotropicout-of-plane (bending) response. Dependingupon the stacking sequence of the individuallayers, the laminate may exhibit couplingbetween inplane and out-of-plane response.An example of bending-stretching coupling isthe presence of curvature developing as aresult of inplane loading.

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Loading

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Info

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The Results Section

Materials Summary

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Micromechanics

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Properties

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Processing-Thermal

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Response

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Theory

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Thermal Models

Transient Condiction in Thick Walled Cylinder

The transient heat transfer code allows one to model multiple materials in a cylinder, eachwith temperature dependant properties. It assumes the barrel is axisymmetric, with no thermalgradient in the axial direction. The solution uses a finite difference method with the governingdifferential equation being:

The initial conditions are:

The boundary conditions used at the inner diameter are:

and at the outer diameter are:

Finally the interface conditions between adjacent radial layers require that:

and

Where T is the temperature, t is time, kr is thermal conductivity, ρ is density, c is specificheat, h is specific enthalpy, and the f and a superscripts stand for the surface subjected tointernal and external, respectively. The property input to this model can be constant ortemperature dependent. Linear interpolation is carried out for each property to determinethe property value at a specific temperature in time.

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Moisture Theory

Moisture Diffusion Theory*

CDS3 includes a moisture diffusion analysis software model for predictingwater uptake, diffusion and internal distribution through the thickness ofmultilayer composite materials by finite difference method. The model includes the effect of of material variation boundary conditionsand layer thicknesses can be studied in real time. Theory will be added in the near future

*Augl, J., M., “Use of finite element analysis for transient moisture diffusion studiesin Multilayer Composites” AEM/S System Sandwich Materials, Nov. 1994. * Augl, J., M., “The effect of Moisture on Carbon Fiber Reinforced Epoxy CompositesIII, Prediction of Moisture Sorption in a Real Outdoor Environment, NSWC/WOL/TR-77-13 1997.

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Structural Mechanics Theories

Thin Plate (Classical Laminate) ModelClassical Laminate theory has been extensively used to describe the behavior of

composite materials under mechanical, thermal, and hygothermal loading conditions. Manyreferences are available where classical lamination theory is utilized to describe compositematerial behavior. In Classical Lamination Theory, the plate is assumed to have infinitedimensions and the whole panel undergoes the same thermal gradients. In this processhowever the heat is applied locally, and the rest of the panel effectively acts as a barrier tocurvature growth. At the completion of every layer or cycle, every point on the panels surfaceexperiences the same thermal history at different times. As a result the thermal signature ofthis process is experienced everywhere but at an offset time corresponding to the timedifference between each point on the surface. Since Classical lamination Theory is timeindependent, this model can be used as a method for determining the stress fields throughthe thickness as long as the panel is sufficiently large. One important difference however isthat since the heated region is local, the solid boundary acts as a mechanism for constraint.This unique boundary is included in the model as a “partial constraint” and the method bywhich it is applied to the model is explained later. The effect of partial constraint is not assignificant in the simplified residual stress model as the heat input is restricted to the surfaceply and the remaining preconsolidated material acts as a similar partial constraint. In thesecond-generation model, the effect of partial constraint becomes a more critical mechanismfor limiting the curvature growth as the actual heat input is applied through the thickness ofthe laminate. This increases the difference in absolute temperatures between the cooler solidboundary and the temperatures within the heat-affected zone.

Basic AssumptionsClassical Lamination Theory predicts the behavior of the laminate within the

framework of the following assumptions. [Pister 1959, Reissner 1961] Firstly, each layer ofthe laminate is assumed to be both quasihomogeneous and orthotropic. The laminate is thinwith its lateral dimensions is much larger than its thickness and that the laminate is onlyloaded in the in-plane directions. This assumption is especially important for the condition ofclamping the laminate. All out of plane displacements are assumed to be small relative to thethickness of the laminate, and in-plane displacements vary linearly through the thickness ofthe laminate. All displacements are small compared with the thickness of the laminate, andnormal distances from the middle surface remain constant. Provided that these conditions aremet, it is possible to determine the reference plane strains and curvatures as a linearsummation of the thermal strains and curvatures for each ply.

A number of important assumptions are made in this simplified residual stressmodel in order to avoid the complexities associated with a moving localized heat source on acomposite laminate. The first assumption in the model is that the panel undergoes the samethermal cycle across the panel surface. Since classical lamination theory is time independent(not including the effects of viscoelastic relaxation) this assumption is valid for a constantvelocity manufacturing process, since every point on the surface observes the same thermalprocessing cycle. So although this analysis cannot provide information about localized residualstresses during panel manufacture it can predict the overall response of the laminate basedon this assumption.

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Composite StrainsThe incremental strains are a function of temperature alone as follows:

where L and t are the coefficients of thermal expansion of the composite lamina and arebased on the micromechanics model and the instantaneous resin properties, fiber propertiesand the volume fraction of fibers. T is the temperature gradient applied to the surface ply.These strains are then transformed to the global coordinate system, through a second ordertensoral transformation of the principle strain increments as follows:

These strains are applied to each layer within the composite to determine the effective plateloads and stresses. The increments in stress and deformation development are computed andsuperimposed to provide a complete profile of the stress field. To carry out this procedure thelaminate is discretized into a number of nodes or layers corresponding to the centerlinedimensions of each ply.

Each layer is assigned a set of thermoelastic properties that are a function of time,temperature and position in the z, or thickness direction. The thermoelastic properties of eachlamina in its principle coordinate system are defined in terms of the plane stress stiffnesscoefficients, Qij. These coefficients are related to the effective constitutive mechanicalproperties of each layer as follows:

The principle coordinate system of each layer or lamina may be orientated at some angle, to the principle coordinate system.

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The lamina properties, , in the global coordinate system are determined from the followingtensoral transformation equations:

The effective in-plane force and moment resultants, when transformed in the global laminatesystem through a second-order tensoral transformation are given by:

where represents the transformed process-induced incremental stress-free strains in

each ply in the global coordinate system, n is the number of plies, and represents thetransformed plane stress stiffness matrix coefficients obtained from the instantaneouscomposite properties of each ply.

The resulting plate loads are then used to compute the effective laminate response in terms ofthe in-plane strains, and curvatures, , through the [abcd] matrix as follows:

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The total incremental ply strains are then computed through the classical strain-displacementequations:

where z is the distance from the laminate mid plane to the ply center. The incremental plystresses are based on the difference between the laminate response strain increments and thestress-free process induced strain increments through the following expression:

The laminate stiffness is obtained by appropriate averaging through the thickness.

The laminate force and moment resultants are found through integration of stresses acrossthe thickness of each lamina.

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Laminate strains are assumed to vary linearly through the thickness as a function of thelaminate mid-plane strains, eo and curvatures, k .

Substituting the assumed strain field into the transformed ply stiffness relations andperforming integration yields the well known laminate stiffness relationship

A general outline of the CLT model described above is shown below. The primary inputs tothis model are the composite material constituent properties; ply thickness, stackingsequence, through thickness temperature gradients, degree of crystallinity and temperaturedependent resin stiffness (if material models are included).

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Flow chart summary for Thermoelastic analysis of laminated composites usingClassical Lamination Theory

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Thick Plate Model (Plane Strain) Theory

In this work, the analytic model developed by Chou et al is used to predict the effectivelaminate stress/strain response. It is also used to calculate ply-level stresses and strainsduring incremental loading for failure and strength prediction. The following section outlinesthe laminated media model upon which our analysis is based.

Chou et al. [2] use a control volume approach to yield a closed-form solution to the problemof effective homogeneous property determination for a laminated media composed ofindividual layers. Unlike the works of White and Angona [24], Postma [25], Rytov [26],Behrens [27], and Salamon [28], which required the individual layers to be isotropic, Chou etal. [2] permitted general anisotropy of the layers. The analysis is based on the assumptionsthat all interlaminar stresses are continuous across ply interfaces and that all in-plane strainsare continuous through the thickness dimension of a representative volume element (i.e., arepeating sublaminate configuration).

The following expression is used to represent the effective (i.e., homogeneous) stress/strainconstitutive relationship for an N-layered laminate (see Figure 1):

Figure 1. Laminate configuration

for (i, j = 1, 2, 3, 4, 5, 6). (1)

The barred notation is used to denote that the relationship applies in the global x-y-zcoordinate system of the laminate. The asterisk superscript is used here to denote the"average" or effective laminate stress and strain quantities. In-plane strains are assumeduniform (i.e., constant within each ply) and equal to the effective strains of the laminate.Mathematically, this is expressed as

for (i = 1, 2, 6; k = 1, 2, ..., N), (2)

where represents the strain in the k th ply of the laminate (see ply numbering conventionin Figure 1). To ensure stress continuity across ply interfaces, all ply stress componentsassociated with the out-of-plane direction (i.e., z-direction) are assumed uniform and equal tothe corresponding effective stresses in the laminate. Mathematically, this is expressed as

for (i = 3, 4, 5; k = 1, 2, ..., N), (3)

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where represents the stress in the k th ply of the laminate.

All remaining effective laminate strains and stresses are assumed to be the volume average ofall their corresponding ply strain and stress components, respectively. Mathematically, theseassumptions are expressed as

for (i = 3, 4, 5) (4)

and for (i = 1, 2, 6), (5)

where V k is the ratio of the original (i.e., undeformed) volume of the k th ply over theoriginal volume of the entire laminate. The constitutive equation for each ply in the laminateis written below (equation (6)) using the superscript notation.

for ( i, j = 1, 2, 3, 4, 5, 6; k=1,2, ..., N). (6)

(For completeness, the ply stiffness matrix coefficients ( ) are defined in terms of thelamina engineering constants and layer orientations in the Appendix.)

Equations (1) through (6) represent 12N+6 linear algebraic equations with 12N+12unknowns. Solution to equations (1) through (6) yields the following effectivethree-dimensional stress/strain constitutive relation, which can be used as an equivalent (i.e.,homogeneous) representation for the laminated media where the coefficients in the laminatestiffness matrix, , are given by

for (i, j = 1, 2, 3, 6), (7)

for (i=1, 2, 3, 6; j = 4, 5), (8)

and

for (i, j = 4,5), (9)

where

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(10)

The effective stress/strain constitutive relation for the laminated media is therefore given byequations (1) and (7) through (10).

In determining the individual ply-level stresses and strains, the assumption is made that the

applied mechanical loading on the laminated media ( ) is known, uniform, and representsthe "average" or "effective" stress acting on the sublaminate configuration. The associated

"effective" or "smeared" laminate strains ( ) can be obtained directly from the inversion ofequation (1). From the assumption made in equation (2), all in-plane strain values (defined inthe global x-y-z coordinate system) for plies 1 through N are therefore known. Similarly, fromthe assumption made in equation (2), all out-of-plane stresses for plies 1 through N areknown (also defined in the global x-y-z coordinate system). The out-of-plane ply strains andin-plane ply stresses remain to be determined.

Sun and Liao [29] derived the following expression for determination of the remaining out-ofplane ply strains

(11)

Once all of the ply strains are known, the remaining in-plane ply stresses can be calculatedstraightforwardly through the following relation

(12)

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Plain strain Cylinder TheoryThe generalized plane deformation analysis presented by Hyer [1] is the basis of this work.

However, instead of formulating a problem in terms of a scaling variable, , such that r. This scalingis done to avoid numerical problems, which is explained later. The formulation is summarized in thepost-consolidation section. The theory has been enhanced significantly to model the effects of windingtension in the insitu-process, and the redistribution of stresses resulting from the removal of the mandrelat any point during the process. Both the post- and insitu-consolidation models incorporate thetemperature dependence of the thermoelastic response of the material. The model is then used toinvestigate the interaction between the cylindrical part and the tool (mandrel), and also the effect ofwinding tension on the residual stresses in the cylinder. It is hoped that this methodology would serve asvaluable tools for the evaluation of the design and performance of both post- and insitu- consolidatedlaminated cylinders under various combination of loading conditions.

Theoretical Development of Post-Consolidation Model

It is desired to determine the response of a laminated cylinder subjected to both mechanicaland thermal loading. The geometry is defined in the cylindrical x--r coordinate system as shown in Figure1. Since only axi-symmetric loading is considered, the stresses, strains and displacements are independentof the circumferential coordinate, . Attention is focused on the response of the cylinder away from theends and therefore the stresses and strains are independent of the axial coordinate, x.

Figure 1. Definition of the Coordinate axes.

The cylinder is composted of N layers, which the innermost layer being referred to as thefirst layer. The inner radius of the cylinder is ri and the outer radius is ro. The interface between the kth

and the (k+1)th is denoted as rk+1. The hydrostatic pressure acting on the outer radius is Po while thehydrostatic pressure acting on the inner radius is Pi. The cylinder is subjected to an axial force Faxial and atorsional load o. Each layer may also be subjected to a thermal loading T(k), where the superscript (k)denotes the kth layer.

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The response of the cylinder is determined from the interaction of individual layers thatcomprise the thickness. The response of each layer is written in terms of constants obtained from theintegration of the elasticity equations for that layer. In general, the set of constants vary from layer tolayer. These constants are determined by enforcing the traction boundary conditions at the inner andouter radii, by enforcing continuity of displacements and tractions at the interfaces between layers, andby enforcing equilibrium of forces on the cylinder.

The constitutive behavior of each layer is expressed in the x--r coordinate system as:

[1]

The terms are the elastic constants and the j terms are the coefficients of thermal expansion ofthe kth layer in the global x--r system, which are obtained by rotating the lamina properties in theprinciple 1-2-3 material system by the winding angle . This rotational transformation of the materialproperties is accomplished using the transformation rules found in any standard textbook on composites[4]. The two transformation systems are defined in Figure 1. As mentioned earlier, the problem isformulated in terms of the scaled variable, . Based on the axisymmetric and plane deformationassumptions, the components of strain for each layer can be expressed in terms of the axialdisplacement, u(x,), the circumferential displacement, v(x,) and the radial displacement w() as follows:

; ; ; ;

; [2]

As shown by Hyer [1], the displacements for the kth layer can be obtained as:

[3]

[4]

From Equations (2), (3) and (4), r = xr = 0, and therefore, from Equation (1), r=xr = 0. The differentialequation governing the radial displacement, w is then obtained as follows:

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[5]

The solution to this equation is:

[6]

where

[7]

and

[8]

The above equations are valid if . For a material that is transversely isotropic in the 2-3 plane (

; ; ; ), the governing differential equation for the radialdisplacement simplifies to:

[9]

whose solution is:

[10]

A1 and A2 vary between layers, while o and o have been shown to be constant for all layers. Therefore,for a laminated cylinder consisting of N layers, 2N+2 constants need to be determined. These constantsare determined by enforcing the traction boundary conditions at the inner and outer radii, by enforcingcontinuity of displacements and tractions at the interfaces between layers, and by enforcing equilibriumof forces on the cylinder. The applicable boundary conditions at the inner and outer radii of the cylinderare

[11]

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The internal pressure Pi is positive in the direction of the outward normal, while the external pressure Po

is positive in the direction of the inward normal. Continuity of displacements at the (N+1) layer interfaceresults in:

k=1,2,….,(N-1) [12]

Application of the condition of equilibrium of forces in the axial direction results in:

[13]

Faxial represents the total axial force resulting from the applied traction Fa in the axial direction, as well asthe axial forces due to the internal and external hydrostatic pressures on the end fittings of aclosed-ended cylinder. For the laminated cylinder under consideration, Equation (13) can be written interms of as follows:

[14]

If the cylinder is open-ended, then the axial forces due to the hydrostatic pressures are absent and onlythe first term on the right hand side of Equation (14) is retained. The integral condition representing theapplied torsion, o, can be written as:

[15]

or in terms of as:

[16]

Equations (11), (12), (14), and (16) provide the necessary 2N+2 conditions required to determine the N*(A1)’s and N*(A2)’s and o and o terms, and therefore the displacements, strains and stresses in each layer.A flowchart of the program methodology is shown in Figure 2.

Theoretical Development for the Insitu-Consolidation Model

In the insitu-consolidation process, the cylinder wall thickness is incrementally increasedlayer by layer. The theoretical basis is the same as in post-consolidation but the mode has been modifiedto incorporate the effects of winding tension and also the redistribution of stresses upon mandrel

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removal. Ghasemi-Nejhad [5] used a finite element approach to model the insitu-consolidation of afilament wound thermoplastic cylinder with a localized heat source. His analysis showed that the resultingstress distribution for insitu-consolidation was axi-symmetric and consistent with the assumptions madein this analysis.

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Figure 2. Flow Chart for the post-consolidation model. In this ‘onion-skin’ model, each layer is added on sequentially, and the incremental strains

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and stresses are due to the addition of a layer are calculated. The layer that is being wound on is subjectto a winding tension, and is at the processing temperature, Tp. This layer is then allowed to cool to themandrel preheat temperature Tm, before the next layer is added. It is assumed that the temperature of allthe other plies is constant at the mandrel preheat temperature. In this manner, the cylinder geometry isbuilt up incrementally, as are the residual strain and stress profiles. The incorporation of winding tensioninto the analysis is discussed in a subsequent section.

The wound cylinder, now uniformly at the mandrel preheat temperature, can then be cooled(or heated) to the operating temperature, Top. In this step, the temperature change occurs uniformly in allthe layers (at this point, the transient heat transfer solution is not applicable to the manufacturingprocess, but is used for stress analysis during firing)

At this point in the analysis, if the mandrel is present, it may be removed. The incrementalstrains and stresses introduced into the composite cylinder on removal of the mandrel are computed bythe mandrel removal analysis. The details of this analysis are presented in a later section.

Finally the response of the cylinder to the mechanical loads is determined. The final states ofstrain and stress are determined by summing up the incremental contributions from all of the aboveprocesses. A flow chart of this process is shown in Figure 3.

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Figure 3. Flow Chart for the insitu-consolidation model.

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Stresses Due to Thermal Loads

In this analysis, it is assumed that the resin has a negligible modulus above Tg, and has itsroom temperature modulus below Tg. The instantaneous thermoelastic properties of the composite arecalculated using continuous fiber micromechanics. Since the properties of the material are assumed to betemperature dependent as described above, the thermal stresses need to be calculated in an incrementalfashion, as shown in Figure 4. At each increment in time, the instantaneous temperature and the Tcorresponding to that time increment is first calculated. Based on the temperature, the instantaneousresin modulus is determined. Continuous fiber micromechanics is then used to determine the effectivethermoelastic properties of the composite lamina in the 1-2-3 lamina reference frame, from which theeffective stiffness constants and the coefficients of thermal expansion in the global system aredetermined through the appropriate rotational transformations by the winding angle . The incrementalstresses and strains corresponding to the increment in temperature are calculated as before.

It should be noted that above Tg, the composite stiffness in the fiber direction may beseveral orders of magnitude higher than the composite stiffness in the transverse direction. Depending onthe orientation of the ply, the parameter (k) defined in Equation (7) may be of the order of 1000. If theproblem had been formulated in terms of r instead of , the term r+1 may cause a numerical overflowfor r>1, while r-+1 may cause a numerical underflow for r<1. The exact value of r+1 or r-+1 which willcause the overflow will depend on the computer system in use. This problem is overcome by scaling thevariable r such that the new variable does not cause this overflow.

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Figure 4, Flow chart for the thermal stress calculation.

Stresses Due to Winding Tension

Cirino [6] included the effects of winding tension in the plane-stress analysis of filamentwound rings. His analysis was, however, limited only to hoop wound rings. The analysis presented hereinis applicable to winding tension at any winding angle.

The layer being wound is subject to a winding tension, , in the fiber direction. Thiswinding tension gives rise to strains in the 1-2-3 principle lamina system, which are given by:

[17]

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The above strains are transformed from the principle lamina system into the global cylindrical systemusing the rotational transformation matrices to yield the strains [w] due to winding tension.

As before, the response of the cylinder is determined from the response of a single layer.The response of each layer is written in terms of constants obtained from the integration of the elasticityequations for that layer. In general, these set of constants vary from layer to layer. These constants aredetermined by enforcing the traction boundary conditions at the inner and outer radii, by enforcingcontinuity of displacements and tractions at the interfaces between layers, and by enforcing equilibriumof forces on the cylinder.

To incorporate the effect of winding tension, the constitutive equation for each layer in thex-q-r coordinate system is modified as follows:

[18]

The strain displacement relations given by Equations (2)-(8) remain unchanged except for equation (8)which is written as:

[19]

As before, the governing differential equation for the radial displacement assuming transverse isotropy inthe 2-3 plane simplifies to:

[20]

whose solution is:

[21]

It may be noted that w can be considered as a stress free strain due to the applied winding tension w, inmuch the same context as T is the stress free strain due to a temperature change T. All of the appliedwinding tension may not be preserved upon laydown [7,8]. The amount of winding tension preserved isdependent on the relative stiffness of the substrate and the layer. The more compliant the substrate isrelative to the layer, the lesser will be the extent to which the winding tension is preserved in that layer.As before, the 2N+2 constants, and hence, the incremental stresses due to the winding tension aredetermined.

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Mandrel Removal Calculations

The filament winding operation is usually done over a metallic mandrel. The mandrel can beincorporated into the above analysis by considering it to be just another layer with the isotropicproperties of the metal. It is now desired to determine the effect of mandrel removal on the stress statein the composite cylinder.

Let x(), (), r() and x() be the stress distributions in the filament wound compositecylinder with the mandrel still in place. It is desired to determine the incremental stresses, x(),(),r() and x() introduced into the composite cylinder upon removal of the mandrel. The state ofstress in the cylinder after mandrel removal will then be [x()+x()],[()+()],[r()+r()] and [x()+x()]. The removal of the mandrel introduces incremental deformations in the cylinder given by:

[22]

[23]

[24]

Note that since T(k) = 0 for the mandrel removal operation, (k) = 0 for all layers. The (2N+2) constantsare determined as before, by the enforcement of the traction boundary conditions at the inner and outerradii, by the enforcement of continuity of displacements and tractions at the interfaces between layers,and by enforcing equilibrium of forces on the cylinder. The boundary condition at the outer radius is nowwritten as:

(since Po = , for mandrel removal) [25]

The boundary condition at the inner radius of the composite cylinder is:

(since Pi=0 for mandrel removal) [26]

or:

[27]

Note here at , since it is the radial stress component between the mandrel and the first

composite layer. Comparing the above to Equation 911), may be regarded as a fictitious internalpressure, analogous to Pi. Continuity of displacements at the (N-1) layer interfaces results in:

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k=1,2,….,(N-1) [27]

Application of the condition of equilibrium of forces in the axial direction results in:

(since Faxial = 0 for mandrel removal) [28]

or

[29]

Note that the integral on the right hand side is evaluated only over the composite layers, the mandrelbeing excluded. The right hand side of Equation (29) may be regarded as a fictitious axial load, analogousto Faxial in Equation (13). Similarly, the integral condition for torsion can be written as:

(since o = 0 for mandrel removal) [30]

or

[31]

The right side of Equation (31) may be regarded as a fictitious torsional load, analogous to o in Equation(16). From Equations (25) thru (31), the (2N+2) unknowns, and hence the contribution from mandrelremoval can be determined. Thus, incorporation of the mandrel removal into the analysis in this mannerautomatically ensures the satisfaction of the displacement and traction boundary conditions, thecontinuity of displacement and tractions at the interfaces between layers and the equilibrium of forces inthe cylinder. The flow chart of mandrel removal methodology is presented in Figure (5).

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Figure 5. Flow Chart for the mandrel removal procedure.

.

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Legal

Disclosure

The material presented is derived from theCDS Software Suite and associated databasesdeveloped at the University of Delaware andis provided as is, without representation as toits fitness for any purpose and withoutwarranty of any kind, either expressed orimplied, including without limitation theimplied warranties of merchantability andfitness for a particular purpose. TheUniversity of Delaware and CCM shall not beliable for any damages, including special,indirect, incidental, or consequentialdamages, with respect to any claim arisingout of or in connection with the USE of theSOFTWARE, even if it has been or is hereafter advised of the possibility of suchdamages.

2010 Center for Composite Materials,University of Delaware, Newark DE 19716

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(Your Appendix goes here)

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Index

- 1 -1D Moisture Diffusion 371D Transient Conduction in a Cylinder 35

- A -Academic Version 19Adding to Materials 29Analysis 32

- C -CDS Input and Output 23Compliant Interlater Model 42

- D -Demo Version 18Disclosure 88Discontinuous Tile Model 41Downloading CDS 11

- E -Experiments 25, 50Exporting Data 49

- H -History of CDS 8

- I -Info 56Installation 12Installation of CDS3.0 license 15Introduction 4

- L -Lamina 53Laminas 28Laminates 31Loading 55Loading and Saving DataLoading Data into CDS 46Loading Experiments 45

- M -Materials Input 52Materials Summary 57Micromechanics 58Moisture Analysis 36Moisture Diffusion Theory 64

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- O -Overview of the Menu Tree 24

- P -Plain strain Cylinder Theory 74Plane Strain Cylinder Model 40Processing-Thermal 60Professional Version 21Properties 59

- R -Response 61

- S -Saving Data 48Screenshots of CDS3.0 9Sources 44Stacking 54Standard Version 20Structural Analysis 38Structural Mechanics Theories 65Supported OS 14

- T -The Input Section 50The Menu Tree 24The Results Section 57Theory 62Thermal Analysis 34Thermal Models 63Thick Plate Model 39Thick Plate Model (Plane Strain) Theory 71Thin Plate (Classical Laminate) Model 65Thin Plate Impact Model 43Transient Condiction in Thick Walled Cylinder 63

- V -Version Overview 17

- W -What's New! 6

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