Hi guys,
I am trying to implement an UMAT subroutine into ABAQUS.
It is a very simple non-linear elastic model, in which the Young's modulus depends on the mean pressure, in details, E=3*(1-2*poisson)*p/kap (where, p is mean pressure, poisson=0.3 is Poisson's coefficient and kap=0.005 is swelling index). The initial stress is 1e5 Pa for sigma11, 22 and 33.
When I run the subroutine , it gives linear behavior with E=3*(1-2*0.3)*(3*1e5/3)/0.05 (which is the Young's modulus calculated with the initial stress). If the initial stress is 0 for all components, it gives us 0 for all calculation because E=3*(1-2*0.3)*(3*0/3)/0.05=0. Obviously, these results are not correct
I would like to ask if you could help me to solve this problem (define the initial conditions as the previous values for each variables).
Thanks in advance
I am trying to implement an UMAT subroutine into ABAQUS.
It is a very simple non-linear elastic model, in which the Young's modulus depends on the mean pressure, in details, E=3*(1-2*poisson)*p/kap (where, p is mean pressure, poisson=0.3 is Poisson's coefficient and kap=0.005 is swelling index). The initial stress is 1e5 Pa for sigma11, 22 and 33.
When I run the subroutine , it gives linear behavior with E=3*(1-2*0.3)*(3*1e5/3)/0.05 (which is the Young's modulus calculated with the initial stress). If the initial stress is 0 for all components, it gives us 0 for all calculation because E=3*(1-2*0.3)*(3*0/3)/0.05=0. Obviously, these results are not correct
I would like to ask if you could help me to solve this problem (define the initial conditions as the previous values for each variables).
Thanks in advance