mfm-test-generator provides a way to generate input files for various targets (finite element solvers, fuel performance code, etc.) for specific test cases.

mfm-test-generator is based on two main concepts:

• test cases, which derives from the AbstractTestCase class. Those class are meant to interpret the input file.
• generators. Generators are related to one test case and one target (finite element solvers, fuel performance code, etc.). From an object describing a test case, the generator generates the input file for its target.

This utility thus proceeds by following these three steps:

1. The input file, written in a JSON-like format, is read.
2. The extracted data is passed to the test case specified in the input file. The test case interprets the data in a form ready to be used by generators.
3. The generators are called.

Usage

A standard invocation of mfm-test-generator is:

$ mfm-test-generator --target=mtest pipe.mfmtg \
                     --@library@="'src/libUmatBehaviour.so'"\
                     --@behaviour@="'umatnorton'"

Command line options

The main command line options are:

• --target which allows specifying one target
• --targets which allows specifying a list of target, separated by commas.
• --targets which allows specifying a list of shared libraries containing user defined ” “test cases or generators, separated by a commas.
• --verbose which allows specifying the verbosity level. Possible choices are: quiet, level0, level1, level2, level3, debug and full.

Syntax of the input file

The input file has a JSON-like interface.

It associates the name to a value as follows:

name: "ssna303"

A value can be a string, a floating-point value, an integer, a boolean, an evolution and a list of times. Values are separated by a comma ,.

Times

Times can be specified using:

1. an explicit list as follows:

times : {0., 1.}

2. an external file as follows

times : {
  file: "data.txt",
  values: 1}

The file field gives the name of the external file. The values field can be:

• a positive integer specifying in which column the time values are read.
• a string giving a formula allowing to interpret the external files. For example, the formula $1*60 multiplies the first column by \(60\).

Evolutions

Evolutions may be specified using:

1. an explicit map between time and values as follows:

outer_pressure: {0: 0, 1:1.e-2}

This means that the value of the outer pressure evolution is 0 at time \(0\) and \(10^{-2}\) at time \(1\).

2. an external file as follows:

inner_pressure: {
  file : 'pressure.txt',
  times: 1,
  values: 2}

The file field specifies the external file name, the times field specifies the column specification for extracting the times (can be a positive integer or a formula), the values field specifies the column specification for extracting the values of the evolution (can be a positive integer or a formula).

Variables expected by standard test case

Test cases shall inherit from the TestCaseBase class which expects the following variables to be defined:

• name (type string, mandatory): name associated with the test case.
• times (type Times, mandatory): list of times.
• author (type string, optional): author of the test case.
• date (type string, optional): date at which the test case has been written.
• description (type string, optional): description of the test case.

Extensions

The MFM_TEST_GENERATOR_ADDITIONAL_LIBRARIES environment variable allows specifying a list of shared libraries separated by commas. Those shared libraries may contain new test cases and/or new generators.

Description of the “UniaxialTensileTest” test case

This test case describes a simple uniaxial tensile test in small or finite strain.

Input file example

test_case: "UniaxialTensileTest",
name: "ssna303",
author: "Thomas Helfer",
date: "30/09/2019",
description: "A first test case",
behaviour: {
  library: @library@,
  function : @behaviour@,
  material_properties: { YoungModulus: 150e9,
                         PoissonRatio: 0.3},
  external_state_variables : { Temperature: 293.15 }
},
times : {0., 1.},
imposed_strain : {
  times:{0, 1},
  values: {0,1.e-2}},

The “ClosedPipeTest” test

Input file example

test_case: "ClosedPipeTest",
name: "pipe",
author: "Thomas Helfer",
date: "30/09/2019",
description: "A first test case",
behaviour: {
  library: @library@,
  function : @behaviour@,
  material_properties: { YoungModulus: 150e9,
                         PoissonRatio: 0.3},
  external_state_variables : { Temperature: 293.15 }
},
// 
inner_radius : 4.e-3,
outer_radius : 4.2e-3,
number_of_elements : 5,
//
times : {0., 1.},
inner_pressure: {
 file : 'pressure.txt',
    times: 1,
    values: 2},
outer_pressure: {0: 0, 1:1.e-2}