Metrics

The metrics command evaluates element quality for an existing finite element mesh and writes one quality value per element (as csv or npy), so mesh quality can be assessed before analysis. Poorly shaped elements — thin, skewed, or inverted — degrade the accuracy and stability of a simulation, and these metrics quantify that shape quality.

automesh metrics --help
Quality metrics for an existing finite element mesh

Usage: automesh metrics [OPTIONS] --input <FILE> --output <FILE>

Options:
  -i, --input <FILE>   Mesh input file (exo | inp | stl | vtu)
  -o, --output <FILE>  Quality metrics output file (csv | npy)
      --log <FILE>     Mirror terminal output to a log file
  -q, --quiet          Pass to quiet the terminal output
  -h, --help           Print help

The available metrics depend on the element type. Each is defined, with acceptable ranges from Knupp et al.¹, on its own page:

• Hexahedral metrics — for eight-node brick elements: maximum edge ratio, minimum scaled Jacobian, maximum skew, and element volume.
• Tetrahedral metrics — for four-node tetrahedral elements: maximum edge ratio, minimum scaled Jacobian, maximum skew, and element volume.
• Triangular metrics — for three-node triangular surface elements: maximum edge ratio, minimum scaled Jacobian, maximum skew, element area, and minimum angle.

1. Knupp PM, Ernst CD, Thompson DC, Stimpson CJ, Pebay PP. The verdict geometric quality library. SAND2007-1751. Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States); 2006 Mar 1. link ↩