Carapace

A WebAssembly-native finite element engine, written in Rust.

A thin, curated engine covering the structural element formulations, material models and analysis types used in practice by PySees, its companion frontend. It runs in a browser Web Worker as a .wasm module, with no server and no OpenSees runtime.

Inspired by OpenSees, but a from-scratch reimplementation.

The Rust crab, half solid red and half a colour-contoured finite element mesh

What it does

2D and 3D frames, trusses, zero-length springs, and plane-stress/strain continuum elements
Fiber sections with displacement- and force-based beam-columns, plus Steel, Concrete, Hysteretic and Pinching materials
Static (load and displacement control, arc-length), modal and transient analysis
Streams results as it runs, with cooperative cancellation, and is checked step by step against OpenSees

API reference

JavaScript / TypeScriptThe wasm API and the input schema, for calling Carapace from the browser. carapace-coreThe Rust engine: elements, materials, solvers and analysis. carapace-wasmThe wasm-bindgen bridge: input decoding and result streaming.

Verification

Test reportWhat each test verifies, against which reference, and whether it passes.