This package introduces nonlinear problems and convergence issues in Abaqus. Solution convergence in Abaqus refers to the process of refining the numerical solution until it reaches a stable and accurate state. Convergence is of great importance especially when your problem is nonlinear; So, the analyst must know the different sources of nonlinearity and then can decide how to handle the nonlinearity to make solution convergence. Sometimes the linear approximation can be useful, otherwise implementing the different numerical techniques may lead to convergence.

Through this tutorial, different nonlinearity sources are introduced and the difference between linear and nonlinear problems is discussed. With this knowledge, you can decide whether you can use linear approximation for your nonlinear problem or not. Moreover, you will understand the different numerical techniques which are used to solve nonlinear problems such as Newton-Raphson.

All of the theories in this package are implemented in two practical workshops. These workshops include modeling nonlinear behavior in Abaqus and its convergence study and checking different numerical techniques convergence behavior using both as-built material in Abaqus/CAE and UMAT subroutine.