**process mat_sim

Description

This post-processor re-simulates material behavior given a strain and parameter (e.g. temperature) history. This post computation is most useful with very large structures and with imported results files. For example, files are much larger than the Z-post files for the same stored results. In that case only the strain need be stored from the FEA run, and additional material state variables can be generated as need-be using this process. This can also be used to re-establish “named” material variables consistent with the material model instead of having SDV indexed names.

Input

The full strain history is required in the variable name eto## listed as full tensor. The dimension will be consistent with the finite element geometry dimension. If the name eto is not directly available (for example with abaqus calculations using *NLGEOM we have LE##) a copy post process can be used beforehand to re-map the name.

If a *parameter option is given the parameters must be in input results as well. The user has the option to re-map those names using the *change_param_name. For example with abaqus results one would specify *parameter NT11 and then re-map that with *change_param_name  NT11 temperature .

Output

The output variables are selected by the user. Before running, the Zpreload command can be run on the material file to get a listing of available material variables.

Syntax

Basic options for this post are:

**process mat_sim [ *change_param_name from-name  to-name ] [ *every_increment ] [ *file fname ] [ *integration ] [ *parameter p1  p2  …  pN ] [ *p_init pval1  pval2  …  pvalN ] [ *rotation ] [ *save v1  v2  …  vN ]

The command descriptions are given below:

*change_param_name

selects if the output will be for every solution map, or just the result at the end of the calculation (or selected maps). If this is not careful use of **output_number 1-999 can allow the user to investigate full material variables at specific points in time.

*file

used to re-name a parameter to be consistent with Z-mat names. specifies the material file (as in standard Z-mat or Z-set input procedures).

*integration

specifies the material integration rule to use rather than the default.

*parameter

specifies parameter names which are to be added and having constant values.

*p_init

specifies parameter values in sequence that they have been defined which represent the initial values. This is important because often the first FEA result map has already had some loading, and thermal strain for example will be calculated based on the temperature difference from the rest state before that results map.

*rotation

specifies the material rotation.

*save

gives a listing of the variables which are desired to be stored in the new results files.

Example

The following example is from Post_test/INP/disk6_matsim.inp

***local_post_processing
 **output_number 1-999
 **file integ
 **elset ALL_ELEMENT

 **process mat_sim
    *every_increment
    *file disk6_matsim.inp

    *parameter temperature
    *p_init    800.

    *integration theta_method_a 1.0 1.e-8 100

    *save_variables
      evi11 evi22 evi33 evi12 evi23 evi31
      eto11 eto22 eto33 eto12 eto23 eto31
      sig11 sig22 sig33 sig12 sig23 sig31
      evcum

Note

The material simulation should always be run from the beginning of the loading history, and following the complete loading path. This is because the material state variables will be tracked, and has substantial impact on the results.