Abaqus#

.inp read + write eager

Summary of the specification#

An Abaqus input deck is a keyword-driven text file. Lines beginning with * introduce a keyword with comma-separated parameters; the data lines that follow belong to it until the next keyword. A mesh needs only two: *NODE, listing an id and its coordinates per line, and *ELEMENT, TYPE=..., listing an element id and its node ids. Named collections are declared with *NSET and *ELSET, and ** starts a comment.

Specification at a glance#

keywords	`NODE`, `ELEMENT`, `NSET`, `ELSET`, `PART`, `INCLUDE`
node line	id, x, y, z
element line	id, n1, n2, … (count implied by TYPE)
element types	C3D4, C3D8, CPS3, S4R, … mapped to polyxios element types
comments	lines starting with `**`; keywords are case-insensitive

Read the full Abaqus specification ↗

Reading#

import polyxios as px

mesh = px.read("model.inp")
mesh.vertices          # (n, 3)
mesh.element_types     # element groups found in the file

Writing#

px.write(mesh, "out.inp")

This codec takes no format-specific options.

Quirks worth knowing#

Node ids need not be contiguous or sorted; they are remapped to a dense 0-based index and the original ids are kept as vertex tags.
*NSET and *ELSET names become vertex and element tags, and an entity in several sets stays in all of them.
Analysis keywords (steps, materials, boundary conditions) are skipped rather than treated as errors.