# Material law integration:¶

Error

**An error occurred due to material law integration problem. Please check your material parameter units or try to use automatic timestepping scheme rather
than manual with smaller initial timesteps under Simulation Control.**

## What happened?¶

The solution diverged due to non-resolution of nonlinear material behavior e.g. plastic material following either the use of non consistent units or larger time step.

## What could be the possible reason?¶

This error may occur when either the units of material are not consistent with the geometry (which may lead to high material or geometric nonlinearity) or the time step for solving the nonlinear material behavior is too large.

## What can I do now?¶

First make sure that the units used for Young’s modulus or stress-strain material data are consistent with the geometry. As a next step make sure that you are using automatic timestepping scheme for the analysis involving material nonlinearity with small initial time step length. An example below elaborates this case:

- Let’s consider a case where material is considered nearly perfectly plastic after the strain value of 0.001 as shown in the stress-strain graph below.

- Now if the simulation is performed such that the initial deformation of the geometry gives the strain larger than the strain where yielding starts (0.001 in this case) using manual timestepping scheme, than the solution will diverge giving this error since it can’t be able to capture the material behavior with in the given time step. To avoid this error, we can use automatic timestepping scheme with fairly small initial time step value such that this nonlinear behavior can be captured easily with in the initial time step(s).

Note

If none of the above suggestions did solve your problem, then please post the issue on our forum or contact us.