StructLabX

2D/3D Frames · Modal Analysis · Response Spectrum · Direct Stiffness Method

A full 2D/3D structural finite element platform built on the Direct Stiffness Method. Place nodes, connect members, assign steel sections, apply nodal and distributed loads, define hinge releases - and run linear static, modal, and seismic response spectrum analyses instantly in your browser.

Whether you’re learning structural dynamics, teaching a course, or need a quick tool for preliminary design and seismic assessment, StructLabX has you covered. Start from a blank canvas or pick one of the ready-made examples.

Frames & Trusses Hinge Releases All Support Types Nodal & Dist. Loads N / V / M Diagrams Reactions & Displ. Stiffness Matrices Steel Sections Stress Diagrams Excel / PNG / JSON Modal Analysis Response Spectrum (EC8 / ASCE7 / IBC / UHS)

New 2D Structure

Blank 2D plane frame canvas

New 3D Structure

Blank 3D space frame canvas

StructLabX | 2D/3D Structural Analysis · Modal · RSA

Examples

Beam Structures

Simply Supported

Single span, UDL

Cantilever

Fixed end, tip point load

Continuous Beam

2-span, interior support

Multi-Span Beam

3-span continuous, mixed loads

Propped Cantilever

Fixed + roller support, UDL

Overhanging Beam

SS beam + cantilever extension

Fixed-Fixed Beam

Both ends fixed, UDL

Frames

Portal Frame

Fixed base, UDL + lateral

Two-Bay Portal

Single-story, 2 bays, fixed

Multi-story

2-story, lateral + gravity

Gabled Frame

Pitched roof, UDL rafters

L-Shape Frame

Column + cantilever

Three-Story

3-story, 2-bay, wind loads

4-Story Frame

2-bay, 4-story, wind loads

Cantilever Building

Core-wall lateral system

Vierendeel Frame

Open-web, rigid joints

10-Member Frame

2-story 2-bay benchmark

Portal Frame - Wind

Fixed base, horiz. UDL on column

2-Story Frame - Wind

2-story, horiz. UDL wind + gravity

Industrial Frame - Wind

Gabled rafter, full wind UDL

Sway Frame - Wind

Pinned base, horiz. UDL, sway

Trusses & Grids

King Post Truss

Simple triangular roof truss

Fink Truss

W-web roof truss

Pratt Truss

4-panel, vertical panel loads

Howe Truss

4-panel, diagonals in tension

Warren Truss

Warren bridge, panel loads

Baltimore Truss

Subdivided Pratt bridge truss

K-Truss

K-diagonal bridge truss

10-Bar Truss

NASA benchmark, 6 nodes

25-Bar Truss

5-panel Pratt benchmark

17-Bar Plane Truss

Cantilever truss, 10 nodes

200-Bar Plane Truss

Grid truss benchmark, 77 nodes

3D Space Frames

3D Cranked Cantilever

L-shaped, out-of-plane load

3D Portal Frame

Rectangular, 4 fixed columns

3D Grid Floor

Grillage (3×3), corner pins

3D Building Frame

2-bay, 2-story, gravity + wind

3D Multi-Storey Office

3-storey, 2-bay, dist. loads

3D Industrial Shed

Wide-span flat roof, 3 frames

Cantilever + UDL

Fixed end, UDL (qy)

Simply Supported + UDL

Pin-roller, UDL (qy)

Column + Lateral UDL

Vertical cantilever, UDL (qz)