What is Classical Lamination Theory (CLT)?

Classical Lamination Theory (CLT) is a mathematical framework for analyzing the mechanical behavior of laminated composite materials. It relates applied in-plane forces and bending moments to mid-plane strains and curvatures through the ABD stiffness matrix, derived from individual ply properties, orientations, and stacking sequence.

Which failure criteria does CLSA support?

CLSA supports seven failure criteria: Maximum Stress, Maximum Strain, Tsai-Wu, Tsai-Hill, Hoffman, Hashin, and Puck. Each ply is evaluated and a safety factor and margin of safety are reported for every criterion.

Can CLSA analyze carbon fiber and hybrid composites?

Yes. CLSA includes a material library with carbon fiber (T300/5208 and others), S-Glass and E-Glass epoxy, aramid (Kevlar), and supports user-defined and hybrid laminates. Weave-pattern knockdown factors for plain, twill, satin, and unidirectional layups are built in.

Does CLSA include a finite element solver?

Yes. CLSA includes a 2D plane-stress FEM solver with automatic mesh generation, configurable boundary conditions, point loads, and visualization of displacement, stress, and strain fields. It complements the analytical CLT engine for structural verification.

Yes. CLSA is completely free. It runs in any modern browser with no installation. Optional account features include saving configurations and using the AI Design Agent (5 free prompts per month for standard users).

Can I export CLSA results to ANSYS, Abaqus, or NASTRAN?

Yes. CLSA exports material and laminate definitions to ANSYS Workbench Engineering Data (MatML 3.1 XML), Abaqus (.inp with *DENSITY and 9-constant orthotropic properties), and NASTRAN (.bdf with MAT8 and PCOMP cards).

What is the AI Design Agent in CLSA?

The AI Design Agent uses a large language model to translate natural-language requirements (loads, weight target, environment) into candidate laminate stacks. Each candidate is then validated with CLT and failure analysis before being presented to the user.

Is CLSA aligned with MIL-HDBK-17 / CMH-17?

Yes. Failure analysis, buckling, and material property handling in CLSA are aligned with the MIL-HDBK-17 / CMH-17 Composite Materials Handbook and verified against standard textbooks (Daniel & Ishai, Jones, Kollár & Springer).

Is CLSA a free alternative to ANSYS ACP?

Yes. CLSA is a free browser-based alternative to ANSYS ACP (ANSYS Composite PrepPost) for early-stage composite laminate design, ply layup definition, ABD/CLT analysis, and failure evaluation. It cross-checks results against ANSYS ACP through a built-in comparison module and exports laminate definitions to ANSYS Workbench (MatML 3.1), Abaqus, and NASTRAN so you can move into full 3D FEA when needed. It is also commonly compared with HyperSizer, ESAComp, Helius Composite, and eLamX.

Can CLSA analyze hybrid composite materials?

Yes. CLSA supports hybrid laminates that mix different fiber types and weaves on a per-ply basis — for example carbon/glass, carbon/aramid (Kevlar), basalt/glass and natural-fiber hybrids. Each ply can use a different material from the library, so interply hybridization, intraply hybrid effects via knockdown factors, and stacking-sequence optimization are all evaluated through CLT and the full set of failure criteria.

CLSA — Free Composite Laminate Analysis

CLSA — Composite Laminate, Hybrid Materials & ANSYS ACP AlternativeCLSA is a free professional web tool for composite laminate analysis and a browser-based alternative to ANSYS ACP (Composite PrepPost): Classical Lamination Theory (CLT), 2D FEM solver, ABD matrix, equivalent engineering properties (Ex, Ey, Gxy, νxy), and failure prediction with Tsai-Wu, Tsai-Hill, Hashin, Puck, Maximum Stress, Maximum Strain, and Hoffman criteria. It also covers thermal residual stress, buckling, interlaminar stress, progressive failure, fatigue (S-N, Miner's rule), filament winding and combined tube loading, and includes an AI Design Agent for generative laminate configuration.CLSA supports laminates and hybrid composite materials made from carbon fiber (CFRP), S/E-glass (GFRP), aramid (Kevlar), basalt, natural fibers and user-defined materials, and exports to ANSYS (MatML 3.1), Abaqus (.inp), and NASTRAN (.bdf). It is aligned with MIL-HDBK-17 / CMH-17 and commonly used as an alternative to ANSYS ACP, HyperSizer, ESAComp, Helius Composite and eLamX. Please enable JavaScript to use the application.Contact