StructLabX

2D/3D Frames · Modal Analysis · Response Spectrum · Time-History Analysis
Pushover Analysis · Structural Optimization · 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, seismic response spectrum, and time-history analyses instantly in your browser. Go beyond linear behaviour with pushover (nonlinear static) analysis - plastic hinges, capacity curve and N2-method performance check - and let the built-in structural optimizer find lighter sections, better node positions and efficient member layouts for 2D frames and trusses.

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) Time-History Analysis (Newmark-β / Wilson-θ) Ground Motion Record Import Ground Motion Intensity Measures PDF Report Export (Charts + Tables) Pushover Analysis (Plastic Hinges · Capacity Curve) N2 Method · IO / LS / CP Performance Levels Structural Optimization (Sizing · Shape · Topology) SQP · Differential Evolution · PSO
New 2D Structure
Blank 2D plane frame canvas
New 3D Structure
Blank 3D space frame canvas
StructLabX | 2D/3D Structural Analysis · Modal · RSA · THA · Pushover · Optimization

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
Semi-Rigid & Spring Elements
Semi-Rigid Portal
Portal frame with rotational springs at beam-column joints
Winkler Beam
Beam on elastic foundation (spring supports)
Spring-Isolated Frame
Two-bay frame with spring supports & link elements
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)
StructLabX | 2D/3D Structural Analysis · Modal · RSA · Pushover · Optimization