Composite Lab
Classical Laminate Theory,
in your browser.
Build ply stacks, compute the full ABD matrix, read engineering constants and failure margins, and inspect the laminate in 2D and 3D — updated on every keystroke.
A complete CLT reference, live.
ABD Matrix
Full 6×6 stiffness with A, B, D partitions, recomputed on every ply edit.
Engineering Constants
Ex, Ey, νxy, Gxy — classified as symmetric, balanced, or quasi-isotropic.
2D & 3D Visualization
Cross-section with fiber-orientation chevrons and an interactive Three.js ply stack.
Failure & Optimization
Tsai–Wu and max-stress margins, plus symmetric-layup search on a Web Worker.
A short primer, for reference.
What is a composite?
A composite is a two-phase material — a stiff, load-bearing reinforcement (typically continuous fibers) embedded in a softer matrix (polymer, metal, or ceramic) that binds the fibers, transfers load between them, and protects them from the environment. The everyday systems: carbon/epoxy (CFRP), glass/epoxy (GFRP), and aramid/epoxy (Kevlar). The whole is genuinely more than the sum of its parts — specific stiffness and strength that no monolithic metal reaches.
Lamina vs. laminate.
A single ply — the lamina — is orthotropic under plane stress: three independent moduli (E₁, E₂, G₁₂) and one Poisson ratio (ν₁₂). Stack several plies at different fiber angles and you have a laminate, whose behavior is governed not just by the constituents but by the stacking sequence. Two laminates made from identical plies can be worlds apart in stiffness, coupling, and failure mode.
Why the ABD matrix matters.
Classical Laminate Theory collapses the whole stack into a 6×6 matrix relating loads and moments to mid-plane strains and curvatures. A (extensional) couples in-plane loads to in-plane strains; D (bending) couples moments to curvatures; B (coupling) is non-zero whenever the layup is asymmetric — which is why an asymmetric laminate warps as it cures and twists when pulled. A glance at ABD tells you the character of the part before a single load is applied.
The four design levers.
Fiber angle, ply thickness, stacking order, and the discipline of symmetry & balance. Symmetric layups zero out B; balanced layups zero out the A₁₆, A₂₆ shear couplings. The canonical starting point, [0/±45/90]s, approximates quasi-isotropic in-plane response while remaining well-behaved in bending. Everything else in this workbench is a tool for turning those four levers with intent.