Bad Material definition in element number
Bad Material definition in element number
(OP)
Hi every body
I have written a VUMAT subroutine for anisotropic hyperelastic material Also, I have introduced material orientation for fiber directions by keywords. . but I have received the error " Bad Material definition in element number".
please give me any suggestion if anyone can help me
I have written a VUMAT subroutine for anisotropic hyperelastic material Also, I have introduced material orientation for fiber directions by keywords. . but I have received the error " Bad Material definition in element number".
please give me any suggestion if anyone can help me 




RE: Bad Material definition in element number
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RE: Bad Material definition in element number
But, I am sure about the material parameters. the code is run without local coordinate. but when I use local cylindrical coordinate, I received the mentioned error.
RE: Bad Material definition in element number
Are you new to this forum? If so, please read these FAQ:
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083
RE: Bad Material definition in element number
about orientation, I have defined a cylindrical orientation for model. I think it must not been specified fiber direction in the keyword for model.In fact, I have considered R direction as direction-1 in the code and I determined angle of fiber direction toward this coordinate for calculating invariant I4 and I6.
In addition, I would like to ask you about calculate cauchy stress. The potential energy function is incompressible, but I add a term of compressibility to function and determine it's coefficient 3 order bigger then other parameters. At the end, I calculate cauchy stress=USU , which S and U are second piola and right cauchy green deformation.