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I am working on a model in which i have a soft layer of material bonded between to rigid layers of material via cohesive elements following a linear separation-traction law based on a critical fracture energy value I determined from experimental and numerical work. I have the interlayer and cohesive elements as one part with a partitioned face and connected to the two adherends via surface-to-surface ties. I have found that my model runs successfully only if the soft interlayer material is made very stiff.

Hi,

We are using the user subroutine UMAT in ABAQUS for varying the material properties in a thin plate. For any static analysis this subroutine is working perfectly fine. However, while using UMAT during natural frequency extraction, ABAQUS is not completing the analysis and is giving a very vague following error message in the log file:

Hi all,

A smooth cylinder in contact with a cylinder that is fitted with one of two irregularities: a 0.4 μm deep groove, or a 7 μm deep groove. the materials are hardened bearing steel and the 440C grade. how to calculate contact pressure distribution   Hertzian pressure for contact with the grooved and smooth surface. 

Looking for your valuable suggestions,directions.

which is a good  book would give answer for the present problem?

Thanks in advance,

Rajesh

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Hi everyone,

I am trying to model composite failure in abaqus. I used USDFLD to check different failure mode (fiber tension/compression, matrix tension/compression,..) based on available theory of failure. After checking the failure, if any element fails, the material property like stiffness will suddenly reduces to near zero. At this time i need to chnage material stiffness in UMAT and getting new stress distribution.

My problem is in the input file (inp file) how can I use both command for USDFLD and UMAT?

 Here is a part of my input file: