Files and Formats

File formats are explained in this section.

This page discusses:

Input Files and Formats

The optimization preprocessor can only read Abaqus input files in free format corresponding to the correct syntax for Abaqus 6.1 and higher. The so-called fixed format (allowed for Abaqus 5.8) is not supported and leads to errors.

Integrating external files in an Abaqus input file by using the option *INCLUDE is permitted. This allows several input files to be used.

Important:

Note, that the *INCLUDE statement cannot be used in other Abaqus commands like for example *NODE. The use of the INPUT parameter is also permitted. The referenced file names must not contain any blanks.

Currently, the use of parts and assemblies in the Abaqus input file is not supported by Tosca Structure. If the input file is not flat, Tosca Structure uses an Abaqus data check run to convert the model data. This might influence the details in the input file, especially the element and node IDs, although the structure stays the same.

When the input file is converted to the flat format using the data check run, the names of the element and node groups change: for a certain instance in an assembly, the groups dealing with its elements or nodes are named

<assembly name>_<instance name>_<group_name>.

These new names should be referenced in the Tosca Structure parameter file if required.

If the input file references an external file with the use of the *INCLUDE option, the flattened input file will contain this included file(s). That is, the flattened version will contain the data in the external files, so that only one input file is generated. If an optimization should consider several parts, it is recommended to configure Abaqus/CAE so that no parts and assemblies are written. To achieve this, the following parameter must be set in the configuration file abaqus_v6.env:

cae_no_parts_input_file=ON

Alternatively, the format might be switched during a Abaqus/CAE session:

mdb.models[modelName].setValues(noPartsInputFile=ON)

Result Files and Formats

By default, Tosca Structure reads the results of the Abaqus FE-Analysis from the binary result database (*.odb file) and binary file (*.sim) formats. The standard result file format is the *.odb format. If the optimization task requires additional information that is not contained in the odb file (for example, stiffness matrices), the request is made automatically.

Further results (for example, stresses at integration points) can be requested by the user without any impact on the optimization. Tosca Structure needs only the results at the end of each step. Therefore, we also recommend requesting other results at the end of the steps to minimize the size of the result file.

Since the *.sim format has undergone development, the compatibility of Tosca Structure 2023 with respect to SIM is guaranteed only toward Abaqus 2023.

Important:

  • The SIM-files from any earlier Abaqus versions than 2023 are not compatible with Tosca Structure 2023.
  • It is recommended to use the .sim file due to significant lower CPU-time for sizing optimization and for sensitivity-based shape and bead optimization.
  • The .sim file is platform compatible opposite to the FIL-file; for example, when copying from a Linux cluster to a local Windows workstation.

Changing the default from *.sim to *.fil is done adding the following command in the parameter file:


DRIVER
  driver.Solver.MatrixFormat = MatrixFormats.FIL
END_

Important:

  • Higher order shell elements often write wrong results in the FIL-file contrary to .sim file having correct results for higher-order shell elements.