Implementation of Lemaitre Damage model with VUMAT subroutine
In this training package, as it is clear in its syllabus, the concept of damage is first explained using the literature reviews. This model is now widely used to deal with coupled damage analyses for various mechanical applications. The Lemaitre model is the damage model that occurs simultaneously with plasticization. And then, Coupled yield equation with the damage equation is presented. Abaqus Lemaitre damage training package is available for solid mechanics students on the CAEassistant shop.
In this package, Firstly, we try to introduce the Lemaitre damage model, including damage mechanics and formulation of the model. Then, writing the Lemaitre subroutine is reached step by step. To do this job, the flowchart of the subroutine, Writing the subroutine line by line, implementation of the subroutine in one element and verification is done. In the last chapter, we implement this subroutine in a complex problem and an upsetting process.
It should be noted that in this damage model, the operator split method is used to solve the equations, and after these equations are solved, the elastic and plastic deformation and their laws are introduced one by one. And it will be explained how to use it in subroutine writing with the help of this theory.
In the next part, the VUMAT subroutine flowchart and its needed inputs and outputs are presented. It should be noted that there are a series of state variables in this subroutine, which can be used to check the outputs given by the subroutine, which include the equivalent plastic strain, the damage parameter, and also the element deletion by another state variable is examined.
Notice: if you are not completely familiar with writing VUMAT subroutines, you should get the VUMAT introduction training package, or if you need more professional information, get the advanced UMAT & VUAMT package version from the website. It should be noted that in this training package, it is necessary to use the Lemaitre VUMAT subroutine due to the hardening topic; you should use VUHARD, too; the VUHARD package is also available in the training packages.
The “Implementation of Lemaitre Damage model with VUMAT subroutine” package is used for shell elements. The equation is based on Finite element simulation of the punchless piercing process with Lemaitre damage model article. If you want to get more information about the Lemaitre damage modeling package, please watch the Demo video.
What is the Lemaitre damage model?
This model is a model whose hardening is isotropic and rate-dependent. Also, the yield is based on the von Mises criterion, which is combined with the Lemaitre damage model.
Is the Lemaitre damage model very different from the ductile damage models? And what is the difference between them?
Yes, this model is different from the normal damage model that exists in ABAQUS and other software. In the Lemaitre damage model, yielding and plasticization occur simultaneously with damage, but in the normal models that exist, the damaged area and the plasticity area are two separate areas.