Introduction to UMAT Subroutine (VUMAT)
During the process of solving each problem, ABAQUS uses a specific program to relate the strain to the stress (the material model). So, If we can not use the material model in ABAQUS/CAE, the user should write the subroutine format known to ABAQUS as UMAT subroutine (in standard solver) or VUMAT subroutine (in explicit solver).
In fact, this subroutine is used to define complex or unusual and novel material models that are not available by default in ABAQUS.
Indeed, this tutorial package contains basic principles and concepts along with practical examples to get acquainted with this subroutine. In the other words, the ultimate goal of this tutorial is to give the user the ability to write UMAT subroutine and VUMAT subroutine to define the mechanical behavior of materials and introduce them to the ABAQUS software. See full information about what you are learning in the drop-down menu by clicking here.
You can find a demo of this package on our channel on YouTube.
Moreover, the general description of how to write a subroutine is available in the article titled “Start Writing a Subroutine in Abaqus: Basics and Recommendations “. You may also like this article to begin writing your own UMAT: Start Writing Your First UMAT in Abaqus
Workshop 1 for UMAT Subroutine
Firstly, in the first workshop, the behavior of the material is an isotropic linear elastic. Firstly, structural equations are fully explained. After that, the lecturer writes the UMAT subroutine and compares the results obtained from the subroutine with the results without the use of subroutine. See full information about this workshop and what you are learning in the drop-down menu by clicking here.
Workshop 2 for UMAT Subroutine
Subsequently, the elastic behavior of orthotropic materials is described in the second workshop. After that, the lecturer writes the UMAT subroutine for the elastic behavior of these materials along with the failure initiation of composite materials and verifies with the results obtained from the graphical environment of ABAQUS software. See full information about this workshop and what you are learning in the drop-down menu by clicking here.
Workshop 3 for VUMAT Subroutine
Thirdly, the elasticity behavior of isotropic material is simulated for brittle materials along with element removal in the third workshop. In other words, the difference between this workshop and the first workshop is using the VUMAT subroutine, considering the failure criterion, and setting the element removal. See full information about this workshop and what you are learning in the drop-down menu by clicking here.
Workshop 4 for VUMAT Subroutine
Finally, a complex example is examined. To clarify, In this simulation, computational plasticity equations are used. That is to say, the lecturer simulates the elastic behavior along with the plastic behavior of the material is also simulated. In conclusion, stress, internal energy, and dissipative energy are the output of the VUMAT subroutine based on isotropic hardening plasticity. See full information about this workshop and what you are learning in the drop-down menu by clicking here.
Mohamed Hassani –
I’m highly satisfied to deal with CAEassistant team in connection with service and support, a really expert group offer best training product on the internet from my experience in term of advanced simulation using subroutine and python scripting. if want to success you should follow a good teacher, for this reason, I encourage student and academic researcher to get touch with them.
William Anderson –
This package was able to give a good view of how to write subroutines in ABAQUS software. The advantage of this training package is complete explanations along with providing complete theories. I think the various and practical examples of this package help a lot to write my own subroutines.
Yasser Saleh –
Great package, it gives you a good idea about getting started with UMAT and VUMAT.
Hanane Bushnell –
In my opinion, this package teaches all the necessary tips to start UMAT and VUMAT writing subroutine . However, it would be much more practical if more advanced examples were added.
Balaji Seenivasan –
This training was very much in line with what I expected. Thank you for giving complete information about writing subroutine to your customers. I also provided the advanced package and I am satisfied with both. Do you also have a consultancy service on writing subroutine for projects?
Experts of CAE Assistant Group –
Thanks.Yes. You can use consultancy service via this link:
https://caeassistant.com/consultancy-application-from/
Vidul Pise –
Thank you for your good training package. Is it possible to prepare a training package for writing subroutine in hyperelastic materials?
Experts of CAE Assistant Group –
It is possible. It depends on how many users request that.
hmenginsoy –
It is a training that has been prepared by a very professional, reliable and expert team in its field and has the feature of creating a solid infrastructure for users. All the examples (they also send you all the application files) are presented in a very clear and explanatory way, by mentioning everything needed one by one (especially how the theoretical principles on different subjects should be applied, etc.). They dealt with everything in detail and quickly (before and after) the training process. Thank you so much.