problem with rate independent problem - Finite Element Modeling
https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/
PolymerFEM.com Discussion Boarden-USFri, 19 Apr 2024 04:55:35 +0000wpForo60
https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-6662
Mon, 09 Mar 2009 20:44:19 +0000Finite Element ModelingJorgenhttps://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-6662
https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-6651
Tue, 03 Mar 2009 06:39:31 +0000http://www.columbia.edu/~jk2079/fem/umat_documentation.pdf-it abropted after some incremenets and I just do it for simle tension test and I think we shouldnt have high distorsions.-in this umat, we use power law for crystalline creep that cause this problem for high value of n (rate sensitivity exponent)f(x)=x|x|^(n-1) which x=tau(shear stress on slip plane)/g(current strengh)-for small value of n it is converged well but for larger value around 100, the problem occured.i think, it is happen because at the beginning, we have small value of x that power by large n.thanksRamin]]>Finite Element Modelingvelvia1000https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-6651
https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-6650
Tue, 03 Mar 2009 05:58:04 +0000Finite Element ModelingJorgenhttps://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-6650problem with rate independent problem
https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-27131
Tue, 03 Mar 2009 02:57:19 +0000I am using crystal plasticity umat written by Huang. but when I set the rate sensivity component n=200(or m=0.005), the ABAQUS can not solve it and give me some error like this.SOLVER PROBLEM. NUMERICAL SINGULARITY WHEN PROCESSING NODE PART-1-1.320 D.O.F. 2 RATIO = 1.07695E+13.andELEMENTS ARE DISTORTING EXCESSIVELY. CONVERGENCE IS JUDGED UNLIKELY.I think it is because we have small number with high value power and it cause singularity.I should say that it is work fine for small n(10 or 20)Please help me.]]>Finite Element Modelingvelvia1000https://polymerfem.com/community/finite-element-modeling-aa/problem-with-rate-independent-problem/#post-27131