FEACrack Home:

When FEACrack is first opened you are presented with the "Home" window. In this window there are 3 fields that can be used. When you open a stored file that has completed generating a mesh, the first screen displayed will be the mesh that has been created.

Choose the unit system for your model. Enter an optional analysis name, and enter optional notes about your model.

Units = kip - in - ksi (there are 6 to choose from)Analysis Name = crack at the toe of the fillet weld connecting the nozzle and shell (this information is for your reference)Notes = (blank) (additional details i.e. type of analysis being run, or client information, etc)

You can save the model now, or at anytime while entering data; you will also be reminded to save the model when generating the mesh.

Once you have completed the fields of your choice click Continue. Note: links to move back and forth through the windows are on each form, and are also located on the tool bar. There are also icons on the left navigation bar to move to each step form.

FEACrack Geometry:

Select the geometry from the pull down menu on the Configuration tab. There are 15 choices in the geometry library including a user defined geometry.

Structural Shape = Nozzle on Shell (There may be one more additional option that can also be selected based on the structural shape, i.e. Weld or Nozzle Type, or none)Nozzle Type = Set on nozzle without pad (alternative option may be available on the geometry)

Save your file and move to the next step form by clicking the right arrow of the Crack icon in the left navigation bar.

FEACrack™ Configuration:

On the configuration tab select the crack location and the mesh symmetry. The number of crack location and symmetry choices will vary for each geometry choice.

External Axial Flaw is selectedThe Model is Half Symmetric (Right Half)

FEACrack Crack Dimensions:

On the Dimensions tab select the crack shape from the pull down menu, and choose either single or multiple crack sizes to evaluate.The Range of Crack Sizes choice gives a spread sheet for the user to enter multiple crack dimensions. A mesh will be generated for each set of crack dimensions. The number of options will again vary for each geometry choice.

Crack Shape = Surface CrackEvaluate = Single Crack SizeCrack Type = EllipticalCrack Length (2c) = 3.5 inCrack Depth (a) = 0.45 in

FEACrack Geometry Dimensions:

Continue entering Dimensions now for the geometry selected. These options will vary depending on the geometry choice. For the example provided there are 3 tabs, Nozzle, Positive X Side, and Negative X Side. Complete the fields on each tab. Since the geometry symmetry chosen for this nozzle example is the right half side of the model, the Negative X shell length is zero. The left side of the nozzle is not present in the right half symmetric model.

Nozzle:Nozzle Length (L_N) = 8 inNozzle Interior Diamater (ID_N) = 4 inNozzle Thickness (T_N) = 0.95 inHeight of Weld (H_W) = 0.8 inWidth of Weld (W_W) = 0.8 in

Positive X Side:Inside Radius (IR_C) = 8 inShell Thickness (T_C) = 1.05 in1/2 Shell Length (L_C) = 16 in

Negative X Side:1/2 Shell Length (L_C) = 0 in

FEACrack Boundary Conditions:

In the boundary conditions window the user enters information about the loading and constraints for the model. On the General tab enter the number of load steps. Usually an elastic analysis will have one load step. If the geometry can contain internal pressure, the Pressure tab is available to enter the internal pressure, if any. On the Constraints tab pull-down menus are available for each location on the model.

Boundary condition locations will vary for each geometry choice. For this right half symmetric nozzle example, constraints such as fixed displacements, forces, and stresses can be applied to the top of the nozzle or the right end of the shell.

General:Number of Time Steps = 1

Option Boxes select or notApply a Temperature Boundary

ConditionEquation Based Crack Face Pressure LoadingTabular Crack Face Pressure Loading

Pressure:Maximum Internal Pressure = 5 ksi

Constraints:Select both the Nozzle and Positive X Side constraints. For each the Displacements and Rotations can be customized or used the default settings.

FEACrack™ Material Model Type:

Click on the Material Properties button on the navigation bar to open the Material Data window. The number of material regions in the model varies for each geometry. The nozzle has three material regions; the shell, nozzle, and fillet weld. The user can enter different material values for these regions. Match the material choice to the analysis type; for this example with a single load step select the elastic behavior.

Assume Elastic Behavior (example selected)Use Deformation PlasticityUse Incremental Plasticity

FEACrack™ Material Properties:

In the Material window the material values may be selected from the pull-down menu or entered by the user. If the Use Defaults option is selected, choose a material from the pull-down menu; many common alloys are available. If the User Specified option is selected, the text boxes are available to enter the material values like Young's modulus of elasticity and Poisson's ratio. No temperature loading was applied in the boundary conditions window for this example, so no thermal properties need to be entered in the material form.

Shell Material = A508 Cl2 & Cl3 ForgNozzle Material = A508 Cl2 & Cl3 ForgWeld Material = ES Weld & HAZ; LA, HHA, 3% NAClUser Specified (selected, information remains the same for each Material section)Young's Modulus = 30000 ksiPoisson's Ratio = 0.3Stress Free Reference Temperature = 0Coefficient of Thermal Expansion = 0

When all the information has been entered click "OK" for each material section.

FEACrack™ Build Mesh:

Next, click on the "Build Mesh" icon. You will be prompted automatically to save the file before building the mesh. The program will now use the information provided to generate the 3D crack mesh. The Wait message window will appear while the mesh is building. Any errors in the input data will be displayed at this time and allow changes to be made before choosing Build Mesh again.

The mesh generation can take several minutes or longer depending on the input parameters and the capabilities of the computer being used.

Once the model has been built use the many View Options to rotate the model in any directions, zoom in or out, or select a predefined view setting (View Type) to examine the mesh details.

FEACrack™ Run FEA:

IMPORTANT: Demo users are required to download the full set of files to run this analysis (the FEA input file is needed). Full Use owners can build the mesh and input file to run the analysis, or use the results files provided in the download.

To select the FEA input files for analysis click on the Run FEA button in the navigation window; the Finite Element Analysis file dialog window will appear. Locate the correct folder in the left window. Use the file type filter from the pull down menu to select the desired type of input file. Highlight the desired file or files in the middle window and click the right arrow to add the input file(s) to the analysis list in the right window. When all the input files have been selected and added to the list in the right window click the Run Input Files button. Each analysis will be run one after the other automatically. For this example select the nozzle_right_half_wrp.inp file and run the analysis.

The time to run each finite element analysis depends on the mesh size (more time needed for more nodes and elements) and the capabilities of the computer being used.

NOTE: A Fatigue Analysis can also be run by full-use owners where the crack mesh is automatically updated as the crack grows. This type of analysis is not available with the demo.

FEACrack™ FEA Results:

When the analysis is finished, click on the FEA Results icon to open the File Selection dialog window. Again, select the correct folder in the left window, and select the result(s) file in the center window. Use the right arrow to add the *_wrp.out result file to the list in the right window. One or more results files can be post-processed together to compare the effect of changing parameters on the crack results. The file type filter can be selected from the pull down menu (different file extensions for each FEA program). Then click on the Refresh Results button; the selected result files will be loaded for viewing.

FEACrack™ FEA Results:

Full Result Image :

The deformed shape of the mesh can be viewed with a stress or strain result superimposed as a color contour. The displacement scale is set by typing a multiplier number in the Displacement Scale text box; try 100 or 1000, etc. A stress result can be selected from the pull down menu. Click the Crack Results button in the navigation bar to get x-y plots of the J-integral, stress intensity K, etc.

FEACrack™ FEA Results:

Cut Result Image:

Allow user to cut sections of mesh out (view is after cut)

FEACrack™ FEA Results:

2D Result Plot:

Allow user to view 2D plots of selected node or element result values.