Week - 10 Hyperelastic Material Models

Modelling a Hyperelastic material from raw data

Hyperelastic material-

these materials have the properties or ability to regain it original shape even after applying large strains, the material may sustain upto 500% of strain.

Aim- to convert the raw material data of hyperelastic material to Keyword properties or ls-dyna mat properties (both Mat-77_O and Mat-77_H)and simulate the model of dogbone specimen to validate the data.

given

engineering stress and engineering strain of material are given data

step 1

obtain the values of all constants in Mat-77_H by giving stress and strain curve as load curve(LCSS) from d3Hsp file

for N=1

C01 and C10 are obtained

for N=2

C01,C10,C11,C22,C20 are obtained

for N=3

C01,C10,C11,C22,C20,C30 are obtained

from d3hsp file true stress and true strain are obtained from which verification are done by converting into e.stress and e stress

then the obtained constants are given as input for all N=1,2,3

the results are as follows and simulated

N=1

the maximum strain is 0.74

the max stress is 1.95 mpa

N=2

the max strain is o.505

the max stress is 1.2 mpa

N=3

the max strain os 0.38

the max stress is 0.8 mpa

the simulation is done results are validated by comparing stress and strains

the data obtained for n2 and n3 are less than n1 because of convergence problems during solving.

the above process is also carried for ogden material constants are obtained

for N=1

Mu1, Alpha 1 are obtained

for N=2

Mu1,Mu-2,alpha 1,alpha 2 are obtained

For N=3

Mu1,Mu-2,alpha 1,alpha 2,Mu-3,alpha 3 are obtained

from d3hsp file the stretch and stress values are obtained and verification is done by comparing values of given

then the obtained constants are given as input for all N=1,2,3

the results are as follows and simulation is done and results are compared and validation is done.

For N=1

the max stress is 1.46 mpa

the max strain is 0.612

for N=2

the max strain is 0.663

the max stress is 1.8 mpa

for N=3

the max stress is 2.3 Mpa

the max strain is 0.65

the simulation is done results are validated by comparing stress and strains the data obtained for n2 and n3 are less than n1 because of convergence problems during solving.

Conclusion-

The given data is converted into both Mat-77_H and Mat-77_O. the obtained data is verified and validated by simulation values. the values are near to accurate values.hence the project is completed.the excel file is attached for verification.