Annex 1

Most frequent error messages reported during the development of the tissue differentiation model and how they were solved.

IN ABAQUS:

1. Error code 11. This error is produced when an array is not appropriately dimensioned. The arrays should have the same order or size as the required field variables to be processed. The environment file should be conditioned simultaneously. Action: increase the dimension array in nodes*elements*required variables
2. Error code 6. The environment file has been not set appropriately. The variables pre-memory, standard_memory and max_history_request need to be increased in the abaqus environment file.
3. Convergence error. The analysis is stopped after a message reporting divergence in the solution. Solution: two aspects exist to be considered. First, change the element type. A non-Hourghess controlled element (see Abaqus user manual) could be appropriate to select when a non-geometry linearity approach is used in combination with biphasic behavior. If after the change of the element type the error message remains, the time limit defined in a step is not low enough, so that ABAQUS is required to find the solution. In the manual an equation is given to calculate this limit. (See section 5.5.1).

Unexpected material names are obtained in USDFLD (variable CMNAME) for some elements. Solution: Model contains parts and assemblies, and then elements are renumbered. Create model without parts and assemblies. Set the environment variable cae_no_parts_input_file=OFF.