DESIGN OF AN ADJUSTABLE DYNAMIC SYSTEM FORCUSTOM ANKLE FOOT ORTHOSES

Ryan Butler, OPS-IIIFaculty Mentor: Jared Howell, MS, CPO

December 2, 2015

DESIGN OF AN ADJUSTABLE DYNAMIC SYSTEM FOR CUSTOM ANKLE FOOT ORTHOSESRyan Butler, OPS-III

The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a dynamic AFO that has provensuccessful in assisting military personnel return to full activity after lower extremity trauma.This project sought to alleviate several issues with the IDEO regarding manufacturability andadjustability by designing an adjustable dynamic system for use in custom ankle foot orthoses.

Prototype development began with a questionnaire to the IDEO team in San Diego togain further information on the device. Attention was then focused on the dynamic elements ofthe product leaving the adjustable attachment to a later project. Beam theory was used toestimate the mechanical characteristics required for these dynamic elements. 3D models werecreated in SolidWorks and evaluated for their performance under static loading conditionsusing FEA.

Results of the beam theory analysis yielded a deflection estimate under a load of 200pounds ranging from 0.7-1.9 inches with decreasing deflection as modulus of elasticity andmoment of inertia were increased. FEA analysis estimated prototype deflection atapproximately 1.8 inches under a load of 200 pounds with a von Mises stress of 58 Ksi.

Both methods of analysis confirmed the need for use of a material with stiffnesscharacteristics similar to that of carbon composites to achieve appropriate deflection. Theseresults further revealed that fine tuning of the dynamic elements is needed in order to optimizeperformance. Subsequent work may include patient trials to determine optimal cross-sectionalarea for given patient weight ranges as well as determining optimal material and manufacturingmethods for the dynamic elements.

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Introduction

The focus of this development project is the design of dynamic ankle foot orthoses

(AFOs). Though the term “dynamic” has not been well-defined, this paper will use the term

“dynamic” to describe those devices which allow for a mechanical dynamic response when

placed under a load. In recent years, the use of composite materials has given rise to various

orthotic designs that allow for better dynamic energy storage and return. For years, prosthetic

feet have been designed to utilize these same principles in allowing amputees to walk and run,

however the technology is still fairly new in the field of orthotics. The purpose of this project

was to develop a novel dynamic component to be used as the energy storing, energy returning

mechanism in an AFO.

Background

During the last decade in the United States, large numbers of wounded military

personnel with lower extremity trauma have returned from service having undergone limb

salvage surgeries. Developments in surgical techniques have allowed them to retain limbs that

in previous years may have been amputated. Though often considered a success, the difficulty

in these cases lies in the fact that many of these patients still struggle to walk and run, often

suffering from chronic pain during ambulation. Additionally, many have seen fellow servicemen

return to full physical activity with the use of a prosthesis after having had an amputation. This

discrepancy has highlighted the need for better orthotic care for higher activity patients.

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To address this problem, orthotic and prosthetic staff at the Brooke Army Military Medical

Center in San Antonio, Texas, developed the Intrepid Dynamic

Exoskeletal Orthosis (IDEO). It consists of a rigid footplate

with medial and lateral extensions connected to a proximal

cuff by two composite rods as shown in Figure 1[1]. It is

available currently at all three major military rehabilitative

hospitals in the U.S. namely Brooke Army Medical Center,

Naval Medical Center San Diego, and Walter Reed National

Military Medical Center. The device has proven effective in

allowing patients to return to high activity including running

and jumping[1,2].

In addition to those who have suffered lower extremity trauma wishing to return to high

activity, there are many other groups who may benefit from a dynamic AFO. This patient

population includes those suffering from pathologies such as CVA, MS, CMT and other

neuromuscular disorders. With more than 795,000 cases each year of CVA alone, this

constitutes quite a large number of patients[3]. Patients who may not be suited for a dynamic

AFO include those with severe hypertonicity or extreme varus/valgus deformities.

Other products currently available that address this patient population include the PHAT

Brace, the Blue Rocker, and AFOs from Dynamic Bracing Solutions. In addition to these three

that have been on the market for some time, the Dynamic Strut AFO and Posterior Dynamic

Element have been added to this group during the course of this project. The PHAT brace from

Bio-Mechanical Composites is a custom AFO that emphasizes a dynamic response to loading

Figure 1: The Intrepid DynamicExoskeletal Orthosis[1]

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and custom, triplanar, biomechanical control. The AFO, however, must be ordered from the

company’s central fabrication facility, and is not post-fabrication alignable[4]. The Blue Rocker

from Allard USA Inc. is an off-the-shelf solution providing some energy return but is mainly

suited for drop-foot and provides little biomechanical control for other pathologies[5]. The AFOs

from Dynamic Bracing Solutions offer custom designs that offer triplanar control and dynamic

response, but these must also be ordered from the company and cannot be made in a typical

orthotic facility[6]. The Dynamic Strut AFO from Coyote Designs presents a solution that can be

made in-house quickly and easily but has not been tested for running and other high impact

activities[7]. The Posterior Dynamic Element (PDE) released earlier this year by Fabtech Systems

has similar features as the Dynamic Strut AFO, but it is also unclear how the device will stand up

to high activity. With the exception of the PDE, none of the devices listed above are post-

fabrication alignable[8].

Research Objectives and Questions

The project began by examining the issues with the IDEO. The IDEO currently makes use

of two composite rods that are part of the Clever-Bone prosthetic pylon system from Medi. One

of the issues with the device is that often a single patient will require multiple devices— one

with stiffer rods for high activity and a second with more flexible rods for everyday use.

Additionally, other problems with the device lie in the fact that it is difficult and time-intensive

to manufacture. These difficulties have limited in the past and continue to limit patient access

to the device. Even within the military hospitals, patients may wait for weeks before their

custom device can be fabricated. The lengthy fabrication time is due in part to the three-stage

lamination process required to laminate composite material around the rods. Additionally, the

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device must be ground out and finished as one piece which requires painstakingly finishing

trimlines with the two rods obstructing access. Lastly, once the device is finished there is no

way to make adjustments to the alignment. This has become an issue particularly with patients

whose condition may change over time[1,9].

Once this background information was obtained, the project turned to addressing these

three issues as a whole— rod interchangeability, manufacturability, and post-fabrication

adjustability. A questionnaire was sent out to those who manufacture and provide the IDEO in

San Diego to gain a better idea of what in their opinion is most needed (see Appendix A for

complete questionnaire). The responses confirmed the need to focus on the manufacturing and

adjustability issues of the device as listed above. Initial concepts consisted of an adjustable

receiver that could more easily be laminated into an AFO allowing for rod attachment at the

end of fabrication. This would not only decrease the number of laminations from three to two,

but it would also allow for easier finishing of the device itself by eliminating the complications

of working around the rods. Additionally, interchangeable attachment of the rods would

alleviate the problem of multiple devices per patient. After considering the scope of the project

and the length of time available, however, the decision was made to focus this project on

designing a better dynamic component leaving the remainder of the design work of an

adjustable connection to a later project.

Methods

Criteria for the overall product were developed based upon the three problems

associated with the IDEO as stated above. The product needed to 1) reduce overall

manufacturing time, 2) allow for alignment adjustments post-fabrication, and 3) allow for

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changing rods post-fabrication. Concepts for the product were generated using a morphological

matrix. The aspects of the product were listed in a row with each of their possible solutions

below. Product possibilities were created from different combinations of these solutions. Once

the top three concepts were chosen, the focus of the project turned to developing the dynamic

component of the product as stated above.

Criteria for the dynamic component were based on the performance of the current rods

used in the IDEO, the Clever Bone system from Medi. It should be noted, however, that the

Clever Bone prosthetic pylon system is a product designed to be used in prosthetic applications.

It is indicated for geriatric patients and those of lower activity with a weight limit of 220

pounds. It is contraindicated for K3 and K4 patients and for heavy physical work[10]. Although it

is difficult to make exact comparisons between prosthetic and orthotic product ratings, it can

be concluded that this product was not intentionally designed for use in high activity orthotic

devices. Notwithstanding, it has functioned quite well as an energy storing element for the

IDEO. The design criteria for the dynamic component of this project were therefore based on

the current dynamic characteristics of the IDEO. Additionally, research performed by the

creators of the IDEO found that the device performed better with the dual rod design when

compared to a single posterior carbon strut[2]. Based on this research, the decision was made to

remain with a dual rod design for this project. Maximum deflection under loading was chosen

as the metric to measure performance of the dynamic component. Due to the lack of published

data on the subject, a range of 0.25-1.5 inches was chosen based on clinical orthotic experience

as an arbitrary, initial target.

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Design of the dynamic component began by estimating the necessary mechanical

characteristics using classical beam theory. The component was modeled as a cantilever beam

in two loading conditions: 1) with a moment applied at the free end, and 2) with a fixed point

load applied at the free end. Because of the difficulty in modelling true loading conditions in an

AFO, both conditions were used in order to gain a range of values that would bracket the true

values. Equations for maximum deflection were used to estimate performance under loading

(see Appendix C for the equations and their corresponding variables). The variables involved in

these equations include length, moment of inertia (cross-sectional area and shape), modulus of

elasticity (material stiffness), and applied load. The length of the rods in the IDEO differs only

slightly from patient to patient, therefore this variable was held constant at eight inches. Using

an excel spreadsheet, a range of values for moment of inertia, modulus, and load was entered

into the deflection equations. In this manner, the effects of each variable were examined

individually.

Based on the results of the beam theory analysis and morphological matrix concepts,

three different 3D models of the dynamic elements were created using SolidWorks as shown in

Figure 2. Model 1 was designed as the primary model for testing and analysis with models 2 and

3 consisting of variations on this design. Model 2 included a different cross-sectional profile

than that of Model 1. Model 3 had the same cross section but its length followed a different

curved path as that of Models 1 and 2. These models were 3D printed using a MakerBot

Replicator 3D printer and examined for overall fit within an AFO. Changes were made to

increase the overall size of the models and were subsequently reprinted on a larger machine.

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Finite element analysis was used to evaluate Model 1 for performance during static

loading. A simple model of an AFO was created in order to mimic loading conditions within an

actual device as shown in Figure 3. The properties of a carbon fiber

composite were chosen as a baseline material and were applied to the

model for the analysis (see Material Properties in Appendix D). A force

of 200 pounds was chosen to represent an average weight, high activity

user. This force was applied axially downward through the proximal

cuff of the AFO while the plantar surface of the footplate was fixed

using a global contact. Using a high mesh quality, the model was

Figure 2: Various renderings of the three dynamic element CAD models

Figure 3: 3D model of asimplified AFO includingModel 1 prototype

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divided into finite elements, and deflection, von Mises stress, and strain were calculated.

Results

Three possible concepts for the overall product were obtained from the morphological

matrix. Concept sketches as well as the complete matrix are given in Appendix B. Results of the

beam theory equations are given in Table 1. Maximum deflection results ranged from 0.36

inches under a load of 100 pounds to 2.41 under a load of 250 pounds by the pure bending and

point load scenarios respectively. Deflection values as calculated by the point loading scenario

were greater in every instance than those calculated by the pure bending equation.

Additionally, deflection increased with applied load and decreased with increasing modulus of

elasticity and moment of inertia.

Deflection results of the finite element analysis simulation are given in Figure 3.

Maximum deflection of the dynamic elements occurred at the most proximal end of the

elements and was calculated to be 1.8 inches. Von Mises stress of 5.821E4 psi was calculated

occurring at the distal attachment of the elements, with a maximum strain of 5.215E-3. The

Condition Load (lbs) Modulus (Msi)Moment ofInertia (in4)

Pure Bending MaxDeflection (in)

Point Load MaxDeflection (in)

Light Load 100 15 0.0012 0.3618 0.9648Medium Load 175 15 0.0012 0.6331 1.6884

FEA Load 200 15 0.0012 0.7236 1.9295Heavy Load 250 15 0.0012 0.9045 2.4119

Low Material Stiffness 175 10 0.0012 0.9497 2.5325Med Material Stiffness 175 15 0.0012 0.6331 1.6884High Material Stiffness 175 20 0.0012 0.4749 1.2663

Small Cross Section 175 15 0.0008 0.9333 2.4889Medium Cross Section 175 15 0.0010 0.7467 1.9911Large Cross Section 175 15 0.0012 0.6222 1.6593

Table 1: Deflection results from beam theory equations for both pure bending and point loading

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complete FEA simulation report is given in Appendix D.

Discussion

The beam theory analysis revealed how each of the variables affects the mechanical

characteristics of the dynamic elements. With regards to load, deflection results varied widely

confirming it will most likely be necessary to design different stiffness elements for different

patient weight categories. This can be done by making small adjustments to the remaining two

variables that were addressed, material modulus and moment of inertia.

The modulus of elasticity is a measurement of a material’s stiffness and varies widely

based on the type of material. The moduli used in the analysis range from 10,000-20,000 Ksi

representative of medium to high quality carbon fiber composites[11]. Although there are other

materials including some metals that exhibit similar stiffness characteristics, composite

Figure 4: FEA simulation results for deflection of Model 1 elements under a 200 pound load

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materials have superior strength-to-weight ratios making them more suitable for this

application. Additionally, because carbon fiber is anisotropic the effective modulus can be

altered depending on the direction the fibers are oriented. This translates to the ability to alter

the stiffness of the elements by adjusting the effective modulus of the material.

The third variable of moment of inertia, however, offers a better solution for fine tuning

element behavior. Moment of inertia is a measurement of geometric stiffness and is affected

by cross-sectional area and cross-sectional shape. Small changes in this value can allow for

small adjustments in element stiffness. Therefore, optimization of the elements can be done

through adjustments to their cross section. This would simplify both material selection as well

as manufacturing complexity by allowing the use of one single material across each stiffness

category.

The finite element analysis simulation revealed that although the current prototype

would not reach its yield strength under the given loading conditions, it would be operating

close to it. This indicates the need for a somewhat stronger design in order to avoid the risk of

product failure. Additionally, the deflection results from the FEA simulation estimate a

somewhat greater than desired flexibility in the elements. If the elements are not appropriately

stiff, they will not provide the proper support to a patient. Again, as mentioned above, this may

be remedied by adjusting the cross-sectional area of the elements.

Though these results provide great insight into the design of the dynamic elements, they

are not without their limitations. It should be noted that for both the beam theory methods as

well as FEA studies only static loading conditions were examined. It is quite difficult to model

the dynamic loading conditions of an orthotic device during human locomotion; therefore,

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static loading was used to provide an estimate. Further, with regards to FEA, while von Mises

failure theory is commonly used for isotropic, ductile materials, carbon composites are by

nature anisotropic and somewhat brittle. A more rigorous approach would be to use the Tsai-

Wu failure criteria for laminates; however, this requires knowing the exact layup and

orientation of each composite layer which has not yet been determined. As a result, von Mises

stress was used as an estimate of prototype failure.

Lastly, dynamics data from the Clever Bone rods as currently used in the IDEO has not

yet been made available to the public. Once available, however, the characteristics of the

dynamic elements from this project can be compared in order to rate their performance against

the current standard. Nevertheless, the results from the beam theory calculations as well as

FEA studies were close to the initial target range of 0.25-1.5 inches connoting that only minor

fine tuning may be needed. Nevertheless, human trials may provide the most useful insight into

actual performance under dynamic conditions as well as feedback on determining the

appropriate stiffness of the elements.

Conclusion

This project sought to alleviate some of the issues seen in the Intrepid Dynamic

Exoskeletal Orthosis by creating a novel dynamic system that can be used in any custom AFO.

The project was successful in creating a set of dynamic elements that can serve as the energy

storing, energy returning component in such a device. Further work includes investigating the

various manufacturing methods for these dynamic elements as well as continuing design work

on their attachment to an AFO.

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The patients that may benefit the most from this product would be those desiring to

return to high activity after a lower extremity injury as well as those who wish to increase their

activity level beyond what is possible in a static AFO. As demand for better outcomes increases

in the field of orthotics, static devices may no longer be adequate to assist patients in achieving

their desired goals. Dynamic devices may provide a viable solution to attaining these better

outcomes, allowing many patients greater mobility and higher quality of life than previously

thought possible.

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References

1. Patzkowski JC, Blanck RV, Owens JG, Wilken JM, Blair JA, Hsu JR. Can an Ankle-FootOrthosis Change Hearts and Minds? J Surg Orthop Adv. 2011;20(1):8-18.

2. Patzkowski JC, Blanck RV, Owens JG, Wilken JM, Kirk KL, Wenke JC, Hsu JR. Comparativeeffect of Orthosis Design on Functional Performance. J Bone Joint Surg Am.2012;94(6):507-15. doi: 10.2106/JBJS.K.00254.

3. CDC Staff. Stroke Facts. Centers for Disease Control and Prevention.http://www.cdc.gov/stroke/facts.htm. Updated March 24, 2015. Accessed November28, 2015.

4. Bio-Mechanical Composites. For Orthotists and Prosthetists. Phat Braces.http://phatbraces.com/practitioners.php. Updated May 2, 2015. Accessed November25, 2015.

5. Allard. Blue Rocker. Allard USA. https://www.allardusa.com/carbon-composite-afos/bluerockertm.html. Updated June 13, 2014. Accessed November 25, 2015.

6. Newman DP. Wounded Warrior takes another step towards his goal. Army.mil.http://www.army.mil/article/30349/wounded-warrior-takes-another-step-towards-his-goal/. Published November 12, 2009. Accessed November 27, 2015.

7. Coyote Design. Dynamic Strut AFO. Coyote Design.http://www.coyotedesign.com/dynamic-strut-afo.html. Updated May 1, 2015. AccessedNovember 27, 2015.

8. Fabtech Systems. PDE Modular Composite Spring System. Fabtech Systems.http://www.fabtechsystems.com/PDE/. Updated October 4, 2013. Accessed November27, 2015.

9. Elston JP, Pyo J, Deben SE. Reconstructive and Prosthetic Options for the WoundedWarrior. Curr Orthop Pract. 2013;24(2):114119.www.medscape.com/viewarticle/780285_print

10. Medi. Medi Clever Bone. Medi. http://www.medi.de/en/international/products/leg-prostheses/energy-returning-components/medi-clever-bone/. Updated August 12,2014. Accessed November 25, 2015.

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11. Corum JM, Battiste RL, Liu KC, Ruggles MB. Basic Properties of Reference CrossplyCarbon-Fiber Composite. Oak Ridge National Laboratory. February 2000.

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IDEO Design Metrics Importance(Scale of 1-10)

Adjustable dorsi/plantarflexion (5 deg) 10Adjustable inversion/eversion (5 deg) 3Adjustable with a standard 4 mm allen wrench 3Rod interchangability (changing from stiffer rods to more flexible) 10Abililty to change from two rods to one 1Importance of maintaining the use of Medi Clever Bone rods (as opposed to an alternate manufacturer, style, etc) 4Maintainin the current size/weight of the device (i.e. not increasing the size/weight) 8Decrease the fabrication process from 3 laminations to 2 8Other not listed (please specify): None

Appendix A

Appendix B

Solution 1:

Design Parameter Rod attachment Mechanism of Adjustment Rod cross section Rod Profile Rod material

Soultion 1 Posterior BoltsSet screws combined withangled surfaces (similar to

pyramid adjustments)Circular Straight Fiberglass

Soultion 2Keyed/notched rodswith locking receiver Shims Oval Contoured to leg Carbon

Soultion 3 Threaded rod endsGraduated angled

connectors on the end ofthe rods

Varied over thelength of the rod

Helical or "X"shaped

fiberglass/carbon mix

Soultion 4Mini pyramids similar

to prostheticattachments

-- Rectangular -- Other Composite

Soultion 5Ball in socket joint

with ball-ended rods -- -- --Non-composite (i.e.

polymer, metal, etc.)

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Solution 2:

Solution 3:

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Appendix C

For a cantilever beam in pure bending:M = bending momentL = length of beamE = modulus of elasticityI = moment of inertia ( ) = 2For a cantilever beam with a concentrated fixed load at one end:W = concentrated loadL = length of beamE = modulus of elasticityI = moment of inertia ( ) = ³3

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Appendix D FEA Simulation of Model1 PrototypeDate: Monday, November 02, 2015Designer: SolidworksStudy name: Carbon 2 DirAnalysis type: Static

Table of ContentsDescription .............................................................. 18

Assumptions................Error! Bookmark not defined.

Model Information.................................................. 19

Study Properties...................................................... 20

Units ........................................................................ 20

Material Properties ................................................. 21

Loads and Fixtures .................................................. 21

Connector Definitions .Error! Bookmark not defined.

Contact Information................................................ 22

Mesh Information ................................................... 23

Sensor Details..............Error! Bookmark not defined.

Resultant Forces...................................................... 24

Beams..........................Error! Bookmark not defined.

Study Results........................................................... 25

Conclusion...................Error! Bookmark not defined.

DescriptionAFO Assembly and Model 1 dynamic elements

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Model Information

Model name: Test Assembly 2Current Configuration: DefaultSolid BodiesDocument Name andReference Treated As Volumetric Properties Document Path/DateModifiedCut-Extrude1Solid Body Mass:0.378764 kgVolume:0.000371337 m^3Density:1020 kg/m^3Weight:3.71189 N

C:\Users\Ryan\Documents\BCM\IDEO Project\CADstuff\FEA Tester Cuff OvalSlots.SLDPRTOct 31 16:44:43 2015Fillet10Solid Body Mass:1.15985 kgVolume:0.0011371 m^3Density:1020 kg/m^3Weight:11.3665 N

C:\Users\Ryan\Documents\BCM\IDEO Project\CADstuff\FEA Tester Footshell2.SLDPRTOct 31 16:44:44 2015Cut-Extrude1[1]Solid Body Mass:0.0355761 kgVolume:3.48786e-005 m^3Density:1020 kg/m^3Weight:0.348646 N

C:\Users\Ryan\Documents\BCM\IDEO Project\CADstuff\Proto 1 - 2D Curvewith ellipitcalprofile.SLDPRTOct 31 16:44:44 2015

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Cut-Extrude1[2]Solid Body Mass:0.0355762 kgVolume:3.48786e-005 m^3Density:1020 kg/m^3Weight:0.348646 N

C:\Users\Ryan\Documents\BCM\IDEO Project\CADstuff\Proto 1 - 2D Curvewith ellipitcalprofile.SLDPRTOct 31 16:44:44 2015Study Properties

Study name Carbon 2 Dir

Analysis type Static

Mesh type Solid Mesh

Thermal Effect: On

Thermal option Include temperature loads

Zero strain temperature 298 Kelvin

Include fluid pressure effects from SolidWorks FlowSimulation

Off

Solver type FFEPlus

Inplane Effect: Off

Soft Spring: Off

Inertial Relief: Off

Incompatible bonding options Automatic

Large displacement Off

Compute free body forces On

Friction Off

Use Adaptive Method: Off

Result folder SolidWorks document(C:\Users\Ryan\Documents\BCM\IDEO Project\CADstuff)

UnitsUnit system: SI (MKS)

Length/Displacement mm

Temperature Kelvin

Angular velocity Rad/sec

Pressure/Stress N/m^2

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Material PropertiesModel Reference Properties Components

Name: Carbon 1Model type: Linear Elastic Isotropic

Default failure criterion: Max von Mises StressYield strength: 4.74e+008 N/m^2

Tensile strength: 4.74e+008 N/m^2Compressive strength: 4.78e+008 N/m^2

Elastic modulus: 4e+010 N/m^2Poisson's ratio: 0.07

Mass density: 1020 kg/m^3Shear modulus: 3e+009 N/m^2

SolidBody 1(Cut-Extrude1)(FEATester Cuff Oval Slots-1),SolidBody 1(Fillet10)(FEA TesterFootshell 2-1),SolidBody 1(Cut-Extrude1[1])(Proto 1 - 2D Curvewith ellipitcal profile-1),SolidBody 2(Cut-Extrude1[2])(Proto 1 - 2D Curvewith ellipitcal profile-1)

Curve Data:N/A

Loads and FixturesFixture name Fixture Image Fixture Details

Fixed-1

Entities: 1 face(s)Type: Fixed Geometry

Resultant ForcesComponents X Y Z Resultant

Reaction force(N) -444.831 444.838 -0.0153842 629.091Reaction Moment(N.m) 0 0 0 0

Load name Load Image Load Details

Force-1

Entities: 1 face(s), 1 plane(s)Reference: Right Plane

Type: Apply forceValues: ---, -100, 100 lbf

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Contact Information

Contact Contact Image Contact Properties

Global Contact

Type: BondedComponents: 1 component(s)

Options: Compatiblemesh

23

Mesh InformationMesh type Solid Mesh

Mesher Used: Standard mesh

Automatic Transition: Off

Include Mesh Auto Loops: Off

Jacobian points 4 Points

Element Size 0.229217 in

Tolerance 0.0114609 in

Mesh Quality High

Remesh failed parts with incompatible mesh Off

Mesh Information – DetailsTotal Nodes 93211

Total Elements 58078

Maximum Aspect Ratio 98.122

% of elements with Aspect Ratio < 3 99.2

% of elements with Aspect Ratio > 10 0.0723

% of distorted elements(Jacobian) 0

Time to complete mesh(hh;mm;ss): 00:00:09

Computer name: KUMPEL

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Resultant Forces

Reaction ForcesSelection set Units Sum X Sum Y Sum Z ResultantEntire Model N -444.831 444.838 -0.0153842 629.091

Reaction MomentsSelection set Units Sum X Sum Y Sum Z ResultantEntire Model N.m 0 0 0 0

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Study Results

Name Type Min MaxStress1 VON: von Mises Stress 0.0773402 N/m^2

Node: 807164.01365e+008 N/m^2Node: 92310

Test Assembly 2-Carbon 2 Dir-Stress-Stress1Name Type Min MaxDisplacement1 URES: Resultant Displacement 0 mm

Node: 2764894.6237 mmNode: 17451

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Test Assembly 2-Carbon 2 Dir-Displacement-Displacement1Name Type Min MaxStrain1 ESTRN: Equivalent Strain 1.96059e-012

Element: 239440.00521454Element: 55976

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Test Assembly 2-Carbon 2 Dir-Strain-Strain1