2D Frame Analysis

A general 2D (plane) frame analyzer. Draw joints and members at any angle, mix steel and concrete sections, apply point / distributed / moment loads in global or member-local directions plus nodal loads, define load cases and combinations, and read axial / shear / moment / deflection diagrams and support reactions for any case, combination or envelope.

Beam Analysis

A continuous beam analyzer (2D frame). Mix steel and concrete members across multiple supports, define point / distributed / moment loads in load cases, build load combinations, and read load-case, combination and envelope forces, deflections and reactions.

Bolt Analysis

Force analysis of an arbitrary bolt pattern under an arbitrary set of loads, by the elastic (in-plane direct shear + torsion, plus out-of-plane tension from axial + bending) or the instantaneous-center-of-rotation (AISC Manual Part 7) method. The elastic method reduces all loads to the bolt-group centroid and reports each bolt's shear and tension; the ICR method reports the bolt-group coefficients C and C′, the instantaneous center, and the per-bolt forces for in-plane eccentric shear. Bolt-group geometric properties (centroid, Σx², Σy², polar J) are reported. Analysis only — no capacity checks.

Cantilever Retaining Wall

A reinforced concrete cantilever retaining wall designed to ACI 318-19. Covers stability (overturning, sliding, bearing) and strength (stem, toe, heel) with optional shear key.

Column Base Plate Design

A steel column base plate on concrete, analyzed by an in-browser MITC4 plate-on-Winkler FEM with compression-only bearing and tension-only anchor uplift (active-set). The concrete bed stiffness is derived from f'c and pedestal height (Ec/h), optionally refined by an allowable soil bearing. Reports concrete bearing (AISC J8), plate yielding, anchor tension/shear (ACI 318-19 Ch.17) and column weld, with a user-selectable anchor-force basis (envelope of FEM and rigid AISC DG1).

Combined Footing

A reinforced-concrete combined footing carrying two columns (exterior + interior) on one trapezoidal footing (ACI 318-19, ASCE 7). Solves the rigid soil-bearing pressure over the trapezoid with partial-bearing liftoff; checks overturning, sliding and uplift; runs a longitudinal beam analysis (shear + moment diagrams) for the top/bottom bars; and designs per-column transverse reinforcement, two-way (punching) shear, the column P-M interaction, and load transfer / dowel development.

Extended Shear Plate Connection

A steel beam-to-column connection where a welded plate extends beyond the beam depth to allow additional bolts, providing increased shear capacity while maintaining flexible behavior.

Flange-Plate + Shear-Plate Moment Connection

A bolted flange-plate moment connection (beam-to-column flange). Top & bottom flange plates carry the moment couple (welded to the column, bolted to the beam flanges) and a single shear plate carries the beam shear, all to AISC 360-16.

Foundation Analysis

A concrete mat / raft (and spread footing) on Winkler soil springs, analyzed by an in-browser plate-bending FEM with automatic uplift detection (compression-only soil). Arbitrary mat shapes with auto-meshing and refinement near columns; reports soil bearing pressure, settlement, plate moments/shears and a bearing-vs-allowable check. (Punching/one-way shear and flexural rebar are follow-up.)

Plate Analysis

A general plate-bending analysis (MITC4/MITC3 Mindlin-Reissner FEM) for slabs and plates of arbitrary shape. Supports pinned / fixed / free edge supports, point and line supports, and an optional elastic (Winkler) bed; carries uniform surface pressure, point and line loads. Reports deflection, plate moments Mx/My, and deflection (L/n) and flexural-stress checks.

RC Column Design

A reinforced concrete column designed to ACI 318-19 for combined axial load and biaxial bending, with the PCA/Bresler load-contour method, P-M interaction diagrams, slenderness and detailing checks.

RC Corbel Design

A reinforced concrete corbel (bracket) designed to ACI 318-19 by the shear-friction method. Covers the vertical load capacity, shear-friction / flexural / restraint reinforcement, main tension steel and horizontal link bars.

RC One-Way Slab Design

A reinforced concrete one-way slab designed to ACI 318-19 for flexure, one-way shear and shrinkage & temperature steel, with minimum-thickness deflection control for simply-supported, continuous and cantilever spans.

RC Stair Design

A reinforced concrete stair designed to ACI 318-19 as a one-way spanning stepped slab between two landings — covering mid-span and landing flexural reinforcement, one-way shear at the landing supports, shrinkage & temperature transverse steel and minimum-waist-thickness deflection control. Matches the Tekla Tedds "RC stair design" workflow.

RC Two-Way Slab Design

A reinforced concrete two-way slab designed to ACI 318-19 by the Direct Design Method — interior panel as a flat plate on columns or with edge beams — covering column & middle-strip flexure in both directions, punching (two-way) and one-way shear, shrinkage & temperature steel and minimum-thickness deflection control.

Single Angle Shear Connection

A steel beam-to-girder shear connection using a single bolted angle, with a coped beam framing into the girder web. Per AISC 360-16.

Slab on Ground Design

A slab-on-ground designed to ACI 360R using the PCA, WRI or Corps of Engineers methods for wheel, dual-wheel, post and vehicle loads, with joint-spacing and crack-control reinforcement checks.

Spread Footing

An isolated reinforced-concrete spread footing under a column with biaxial eccentric load (ACI 318-19, ASCE 7). Solves the rigid soil-bearing pressure with partial-bearing liftoff, checks overturning, sliding (passive + friction) and uplift stability, and designs the footing for one-way (beam) and two-way (punching) shear, biaxial flexure, the column/pedestal P-M interaction, and load transfer / dowel development at the column interface.

Steel Composite Beam Design

A steel beam acting compositely with a concrete slab on metal deck, designed to AISC 360-22 (LRFD/ASD). Covers construction-stage flexure (with LTB) and shear, shear-stud design for full/partial composite action, composite-stage flexural strength, and the serviceability deflection checks. Supports secondary (tributary) and primary (point-loaded) beams.

Unit Converter

A free-form engineering unit converter: enter a value, pick a source and target unit from searchable dropdowns, and convert instantly. Covers every quantity mathjs knows — length, area, volume, mass, force, moment/torque, line loads, density, pressure/stress, temperature, energy, power, angle, time, speed, frequency, and the full electrical/magnetic set (current, voltage, charge, resistance, capacitance, inductance, conductance, flux), plus substance, luminous intensity and data. Incompatible units are flagged as "Not compatible" with clickable suggestions of compatible units. Powered by mathjs.

Weld Analysis

Weld-group analysis for an arbitrary set of weld lines under an arbitrary set of loads, by either the elastic ("treat the weld as a line", Blodgett / AISC J2.4) or the instantaneous-center-of-rotation (AISC Manual Part 8) method. The elastic method reduces all loads to the weld-group centroid, computes the line moments of inertia (Ix, Iy, J), and reports the peak force-per-unit-length resultant (direct shear + torsion + axial + bending) against the AISC J2.4 weld strength. The ICR method finds the instantaneous center for in-plane eccentric shear and reports the connection capacity and coefficient C. Supports LRFD/ASD, an optional directional-strength bonus, and a bearing-backed compression option.