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DDSDDE for Composite material.


atra
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 atra
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Helloo all....

I have written UMAT for glass fiber composites. [U]It works fine till failure then it fails to converge:(.[/U]

I understand problem lies in non linear tangent stiffness. I am supplying calculated stiffness matrix to DDSDDE.

[B]Can any one help or suggest most accurate coding of DDSDDE for my problem..????[/B]

Thanx in advance...

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Jorgen
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Im not quite sure I understand your question. If your DDSDDE matrix is not accurate enough, then can you not simply derive a more accurate version?

-Jorgen

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atra
Posts: 7
 atra
Topic starter
(@atra)
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Joined: 7 years ago

I dont know what should I supply to DDSDDE.

I coded USDFLD instead of UMAT. I am having good agreement with experimental results.

I want to know that does ABAQUS have inbuilt non linear model for isotropic material..????

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Jorgen
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It can be quite challenging to derive an accurate DDSDDE (Jacobian).

I have derived & implemented a library of non-linear material models that can help accurately predict polymer behaviors (PolyUMod).

-Jorgen

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