Constitutive model implemented in calculation code, play an important role in the material behaviors prediction. In the field of geotechnical engineering there are numerous soil constitutive models. By installing these models in a finite element code such as Abaqus, their development, efficiency and advancement can be increased. Also, more and more complex engineering problems can be solved by this method. But to do this, you need a proper understanding of the mathematical and programming basics of these models. This tutorial focuses on implementing advanced constitutive models in Abaqus, particularly for simulating soil behavior. Focusing on the CJS model, this tutorial tries to teach how to work and how to program these models in Abaqus code. It includes detailed explanations of VUMAT and UMAT subroutines and practical examples of implementing the CJS model.

Note: In this project, we have discussed the UMAT and VUMAT subroutines, their specifications, and features. You will become familiar with the implementation of both UMAT and VUMAT subroutines. However, the specific focus of this project, for which we have provided the necessary files and run the analysis, is on using the VUMAT model. If you need to use Abaqus for this project with the standard solver, you will need to write the UMAT subroutine yourself.