Fiber-based section analysis
Run moment-curvature and axial-load–moment interaction analysis — at any bending angle — on reinforced-concrete and prestressed sections, right in your browser. Discretize the section into fibers, apply confined and unconfined concrete models and reinforcing-steel models, explore the results visually and interactively, and export them to a professional PDF report.
3D & 2D interaction diagrams
A 3D interaction surface and 2D envelope curves, plus backbone curves you can inspect for any angle.
Moment-curvature curve
The full M–φ response computed at any loading angle, with energy-based idealization, step-by-step section-stress animation and detailed data tables.
Fiber material models
Different concrete models for the core and cover (confined/unconfined Mander, Hognestad) and steel models with or without strain hardening. You set the material grades.
Prestressed sections
Add prestressing tendons to analyze prestressed and ordinary reinforced-concrete sections alike.
Professional PDF report
Generate a detailed PDF report — with the moment-curvature summary, material curves and fiber stress/strain profiles — carrying your firm's logo.
Publish & verify
Freeze the calculation as an immutable copy and get a public verification link. Anyone you share the QR-coded PDF with can confirm it's genuinely yours and unchanged.
Questions
- What is nonlinear fiber section analysis?
- The section is divided into small fibers; each concrete, steel and tendon fiber follows its own stress–strain law, and equilibrium across the section is solved with a dedicated convergence algorithm. The lumped- and distributed-plasticity properties needed for nonlinear performance analyses are computed this way.
- Which material models are used?
- Mander for the confined core concrete; Hognestad or unconfined Mander for the cover. Reinforcing steel can use elastic-perfectly-plastic, bilinear, trilinear and OpenSees02 models, and prestressing tendons use a Ramberg–Osgood model.
- Can I analyze prestressed sections?
- Yes. You can add prestressing strands alongside the reinforcement, or analyze prestressed sections with tendons only and no rebar. Place the tendons at any position or distribute them evenly around the section, and enter the tendon force as the net prestress after losses.
- Is section analysis free?
- Fiber Section Analysis is a premium calculation included in the Engineer plan. You can try it free.
Start calculating in minutes.
Sign up, pick a calculation, and produce your first auditable report.