Laminate Properties
laminate_propertiesComputes effective stiffness, thermal warp, and first-ply failure of bonded multi-layer composite stacks. Provides closed-form screening before detailed FEM analysis.
Instructions
Effective stiffness, thermal warp, and first-ply failure of a bonded
multi-layer composite stack (NO solver) — the closed-form screening twin a
layered multi-material CalculiX fem_run static solve is gated against (e.g.
1 metal layer + 1 plastic layer, or any [(material, thickness), …]).
layers is the stack bottom→top; each entry is a mapping with a thickness
(mm) and either a corpus material name or explicit E/youngs_mpa/
youngs_gpa (+ optional nu/poisson, yield_mpa, cte/cte_per_k,
density_kg_m3, thermal_conductivity_w_mk); explicit values override the
card. width_mm scales EI / first-ply. Optional delta_T (K) gives the
bimetal thermal curvature; force_n (in-plane, total across width) and/or
moment_nmm (about the neutral axis) give the first-ply margin.
Computes the in-plane modulus (Voigt rule-of-mixtures parallel, Reuss series
through-thickness); the transformed-section neutral axis, EI_eff, and flexural
modulus E_flex = 12·EI/(b·h³); the CLT A/B/D matrices per unit width (B ≠ 0 ⇒
bending–extension coupling / warp warning); mass-averaged ρ, stiffness-weighted
in-plane CTE, series/parallel thermal conductivity; the transformed-section
bimetal curvature (= Timoshenko's two-layer formula exactly, also reported);
and per-layer extreme-fibre stress → margin to yield → governing layer + load
to first yield. A single-material stack reduces to that material's E / EI; a
symmetric stack gives B = 0; ΔT = 0 or zero CTE-mismatch gives zero curl.
Escalate to a layered fem_run solve for thick stacks, anticlastic curvature,
free-edge interlaminar stress, or non-isotropic plies.
Returns {n_layers, width_mm, total_thickness_mm, layers, E_inplane_mpa, E_through_mpa, neutral_axis_mm, EI_eff_nmm2, E_flex_mpa, A_matrix, B_matrix, D_matrix, coupling_ratio, asymmetric, rho_eff_kg_m3, cte_eff_per_k, k_through_w_mk, k_inplane_w_mk, delta_T, thermal_curvature_per_mm, radius_of_curvature_mm, timoshenko_curvature_per_mm, applied_force_n, applied_moment_nmm, kappa_applied_per_mm, axial_strain, layer_stresses, first_ply, fidelity, band_pct, valid_range_ok, warnings, escalate_to}.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| layers | Yes | ||
| delta_T | No | ||
| force_n | No | ||
| width_mm | No | ||
| moment_nmm | No |