Configuration file reference#

This page documents every field of the PreVABS JSON configuration file. For an introduction to what configuration files are, where they are loaded from, and how the levels are merged, see the guide page Configuration files.

A configuration file is a JSON object. All sections and all fields are optional; any field that is omitted keeps its value from a lower-priority level (or its built-in default). Unknown sections and fields are ignored.

Listing 16 All configuration sections with their default values.#
{
  "numerics": { "tol": 1e-12, "geo_tol": 1e-9 },
  "output":   { "log_level": 2, "gmsh_verbosity": 2 },
  "tools":    { "vabs": "VABS", "swiftcomp": "SwiftComp", "gmsh": "gmsh" },
  "paths":    { "material_db": "" },
  "gmsh":     { "general": {}, "homogenization": {}, "recovery": {} }
}

numerics#

Numerical tolerances used in geometric computation.

  • tol - Intersection-parameter tolerance. Number. Default 1e-12. Equivalent to the XML <general><tolerance> value.

  • geo_tol - Initial geometry tolerance. Number. Default 1e-9. The cross-section reader replaces this with a model-scale value before component geometry is built, so this is only the starting point.

output#

Logging and Gmsh message verbosity.

  • log_level - Verbosity of the PreVABS log. Integer 0–5, where 0 = trace, 1 = debug, 2 = info, 3 = warning, 4 = error, 5 = fatal. Default 2 (info).

  • gmsh_verbosity - Verbosity of Gmsh messages. Integer, one of 0 (silent), 1 (errors), 2 (warnings), 3 (info), 5 (debug). Default 2. The command-line flag --gmsh-verbosity overrides this.

tools#

Executable command names or paths for the external programs PreVABS launches. Each value may be a bare command name — resolved through the system PATH — or an absolute path, which is used verbatim.

  • vabs - VABS executable. String. Default "VABS".

  • swiftcomp - SwiftComp executable. String. Default "SwiftComp".

  • gmsh - Gmsh executable. String. Default "gmsh".

paths#

Default file locations applied on every run.

  • material_db - Full path to a material-database XML file read on every run. String. Default "" (empty). When empty, PreVABS uses the built-in default MaterialDB.xml located next to the executable (read only if present). When set, the configured file is read and a missing file is an error. In either case this database does not replace the input’s <include><material> database, which is still read independently; materials and laminae with the same name defined later override earlier ones.

gmsh#

Gmsh visualization options for the generated .opt file, grouped into sub-sections. Object. Default {}.

  • general - Options written for every analysis.

  • homogenization - Options written additionally for a homogenization run.

  • recovery - Options written additionally for a dehomogenization / failure (recovery) run.

Each sub-section is an object mapping a raw Gmsh option name (for example "Mesh.ColorCarousel") to its value. For a run PreVABS writes the general block followed by the block for the current analysis. Values are written verbatim into the generated .opt — numeric values as-is, string values quoted. Entries merge per key across config levels (a higher level updates or adds individual options without discarding those from lower levels).

The default view options ship in the prevabs.json located next to the executable (config level 2); edit or empty its gmsh section to change or suppress them. See Configuration files for details.

PreVABS does not validate the option names or values; it only passes them through. An invalid option is reported by Gmsh itself when the .opt file is loaded (which only happens when visualizing with -v), and does not affect the analysis results.