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The Establishment And Verification Of Dynamic Model Of Foot-Sneaker Finite Element Based On Two Coupling Methods

Posted on:2022-06-06Degree:MasterType:Thesis
Country:ChinaCandidate:Y YangFull Text:PDF
GTID:2557306326954789Subject:Human Movement Science
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Objective:By comparing the simulated plantar pressure of two kinds of coupled foot-sneaker finite element models to ascertain the difference of bonded and frictional coupled methods.Before establishing dynamic foot-shoe finite element analysis of running it must to verify bonded and frictional foot-sneaker models.And then comparing experimental and simulated vertical ground reaction force to verify dynamic running finite element analysis that loading kinetic parameters of human running test.For this study the comparison of bonded and frictional coupled foot-sneaker models would confirm which method of building coupled finite element model was close to real foot-shoe system,and the dynamic analysis would help researchers to study boundary conditions of making foot-sneaker finite element models to move as real human running.Method:Using computed tomography scan technology to obtain two dimensional medical image data of subject’s right foot within experimental sneaker.Then choosing Mimics 19.0 software to create foot and sneaker three dimensional models.Combining foot bones by ligaments and plantar fascia which simulated by line bodies in ANSYS 19.1 software and coupling foot and shoe models also using it.For stand simulation it was performed by statistic structure module in ANSYS WORKBENCH and for human running simulation it was performed by transient structure module in the software.About human running test it was performed by Footscan pressure test system,Pedar pressure insole,Kistler force test platform and Motion high speed motion capture system to obtain subject’s sole and plantar pressure when static stand and dynamics and kinematics parameters when running test.Test sole and plantar pressure would be segmented regions and compared with static stand simulated pressure results to analyze difference between bonded and frictional finite element models.The distances and rotations of foot about running results would be as boundary conditions to actuate foot-sneaker model running.The vertical ground reaction force of running test would be as a verification to validate the dynamic finite element analysis.Results:(1)The sole pressure of bonded model was similar to the measured results but simulated plantar pressure was not.The peak plantar pressure of bonded model was concentrated at toe(0.503KPa)however the measured peak plantar pressure was concentrated at heel and the error of average plantar pressure was 320.26%.(2)The sole and plantar pressures of frictional model were similar to the measured results and the errors of average sole and plantar pressures were 7%and 15.5%.The peak plantar pressure of simulation(0.086KPa)was concentrated at heel as same as experimental results.The results of frictional foo-shoe model were closer to measured values than bonded model.(3)For bonded foot-shoe model the first peak of vertical ground reaction force was close to 1600N and the curve of simulated ground force was similar to running test result when cushion stage.However after cushion stage the curve of simulated ground reaction force was greatly different from measured result.The goodness of fit between bonded model and real test were all below 0.6.(4)For frictional foo-shoe model the first peak of vertical ground reaction force was close to 1600N and the simulated curve of reaction force shows good similarity to measured reaction force curve for all running stages.The goodness of fit between the simulated and measured curves of the friction-contact model is above 0.8.(5)Choosing kinematics of human running as boundary conditions to motivate foo-shoe finite element model moving could obtain internal dynamics of running simulation as same as real human running.The simulation results of the friction model are closer to the measured results than the bonded model.Conclusions:(1)The validation of partition pressure about sole and plantar simulation can comprehensively analyze and verify foot-sneaker finite element models.It’s suggested that the validation of section pressures are comprehensive and scientific for foot-sneaker finite element analysis in the future.(2)The frictional model can simulate real force reaction of human feet with sneakers better than bonded model.It is recommended to choose the frictional method to couple foot model and shoe model in future researches.(3)It is feasible to select kinematics of human running as boundary conditions to do running dynamic simulations of finite element analysis.The vertical ground reaction force simulated by frictional foot-sneaker model has a high similarity with the running test results.It is suggested that the dynamic running simulation can be carried out by using kinematics parameters of human running tests.
Keywords/Search Tags:finite element model verification, foot-sneaker finite element analysis, static finite element analysis, dynamic finite element analysis
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