| name | calculix-sizing-optimization |
| description | Workflow skill for two-stage sizing/parameter optimization on a CalculiX shell or beam deck via the optimize_structure tool — Latin Hypercube sweep plus coordinate descent to minimize mass subject to stress/displacement or natural-frequency constraints by tuning scalar section/material/load cards. Use when an agent must lighten a CalculiX shell or beam model while keeping stress and deflection within limits, or must thin a deck until its first modes clear a resonance floor (freq_1_hz constraint on a *FREQUENCY deck). |
CalculiX Sizing Optimization
Two-stage sizing/parameter optimization: minimize mass subject to stress,
displacement, or natural-frequency constraints by editing scalar design
variables in place (shell thickness, beam section, material E/nu/density, load
magnitude). The mesh and geometry never change — only scalar cards.
This is sizing optimization, not topology optimization. It thins sections;
it does not redistribute material in space.
When to Use
Use when an agent must lighten a CalculiX shell or beam model while keeping
von Mises stress and displacement within limits (static deck), or must lighten
it while keeping a natural frequency above a resonance floor (modal deck).
Driven by the optimize_structure_tool MCP tool.
Do NOT use for:
- Solid (C3D8 / C3D8R) models. Solids expose no scalar geometry card — their
mass is set by node-defined volume x density, so there is no thickness to
thin. Material/load variables on a solid are degenerate for mass minimization
(density changes mass but not stiffness; E changes stiffness but not mass).
Solid lightweighting needs shape or topology optimization, which is a
different problem and is not covered here.
- Topology optimization (material distribution over a fixed mesh) — separate,
future work.
Workflow
parse_inp / list_design_vars_tool — confirm the deck and find the
(or beam section) and its current value.
