Free 2D Frame and Truss Analysis Software

Model and analyze custom 2D frames, trusses and mixed structural systems online. Free analysis includes reactions and axial, shear and bending response, with three anonymous previews of complete displacement results.

  • Moment-resisting and pin-ended members
  • Force and moment diagrams
  • Standard and custom sections
  • Metric and imperial
  • Load workflows and reports
Always free Core analysis without an account
Model geometry and supports Standard and custom sections Reactions and member-force diagrams
Checking your three free displacement previews…
7-day free trial Unlock the complete 2D workflow for 7 days

Unlock complete displacements on every run, load workflows, cloud saving, PDF reports, Optimal AI and project history.

Start free 7-day trial View plans How to use 2D Analysis

2D Structural Analysis

Frame & truss workspace
Local recovery ready
100%
New structural model

Start a 2D frame or truss analysis

Draw from a blank grid, open an editable example, or use Optimal AI to propose the starting model.

Browse examples
Popular examples

Moment-resisting frame members and pin-ended members can be combined. Joint-loaded pin-ended models reproduce ideal truss axial response.

⌘K
x 0.00 m   y 0.00 m
Select an item to edit its properties
Nothing selected

Editable structural models

Example frame and truss analyses

Load a complete model, inspect its geometry and inputs, then change the restraints, loads, materials or member behavior before you run the analysis.

Frame analysis

Single-bay portal frame

A 6 m by 4 m rigid frame with fixed bases, a roof distributed load and a lateral nodal load.

  • Support reactions
  • Shear and moment diagrams
  • Frame sway and displacement
Open editable example
Mixed model

Braced two-storey frame

Frame beams and columns combined with released diagonal braces under gravity and lateral loading.

  • Moment-resisting and pin-ended members
  • Brace axial forces
  • Storey displacement
Open editable example
Frame analysis

Gable portal frame

Inclined rafters and rigid columns with distributed roof loading on both slopes.

  • Inclined members
  • Rafter and column moments
  • Horizontal reactions
Open editable example
Truss analysis

Warren truss

A repeating triangular web system under vertical loads applied at the upper joints.

  • Triangular geometry
  • Axial-force distribution
  • Deflected shape
Open editable example
Truss analysis

Triangular roof truss

A pitched four-panel roof truss with vertical loads applied at the upper panel points.

  • Roof-truss geometry
  • Chord and web forces
  • Vertical deflection
Open editable example

Browser-based structural solver

2D structural analysis for frames, trusses and mixed models

Optimal Beam is an online structural analysis calculator for planar structures assembled from nodes and straight members. Define the analytical geometry, assign restraint and stiffness properties, organize structural loading, and review reactions, displacements and member actions without installing desktop software.

Moment-resisting frame members and pin-ended members can be combined in one model, allowing frames, trusses and braced structures to be analyzed in the same workspace. Connection behavior is assigned individually rather than forcing the entire project into one mode.

Frame calculator

2D frame analysis calculator

Analyze portal frames, gable frames, braced bays, multi-bay frames and multi-storey planar structures. Frame members include axial and flexural stiffness, allowing the solver to calculate axial force, shear force, bending moment, joint rotation and structural displacement.

  • Horizontal, vertical and inclined frame members
  • Continuous, start-released or end-released connections
  • Nodal forces and moments
  • Member point, uniform, partial and varying distributed loads
  • Reaction, axial, shear, moment and deflected-shape views

Truss calculator

2D truss analysis calculator

Build custom plane trusses using pin-ended members and loads applied at the joints. Under this idealization, the members develop axial tension or compression without end-moment transfer. Start from a Pratt, Warren or roof-truss example, then edit its geometry, supports and loading.

Structural truss analysis

Apply loads at panel points for an ideal pin-jointed truss model. Loads applied directly along a member produce local shear, bending and deflection because the member retains frame flexural stiffness. The tool does not estimate roof pitch, lumber quantities, fabrication dimensions, connection capacity or truss manufacturing requirements.

Member-level behavior

Moment-resisting versus pin-ended members

Both choices use the same axial and flexural frame formulation. Pin-ended behavior releases both end moments; joint loads reproduce ideal truss response, while span loads can create local shear and bending.

BehaviorMoment-resisting frame memberPin-ended member
Axial stiffnessIncludedIncluded
Flexural stiffnessIncludedIncluded within the span
End-moment transferContinuous unless releasedReleased at both ends
Joint-loaded idealizationAxial and bending responseAxial tension or compression
Direct transverse member loadLocal shear, bending and deflectionLocal shear, bending and deflection with zero end moments
Use in a mixed modelYesYes

Modeling workflow

How to use the 2D structural analysis software

Move from analytical geometry to a solved model in six steps. Every item remains editable after it is drawn.

  1. 1

    Create nodes

    Use grid snapping or enter exact X and Y coordinates in the properties panel.

  2. 2

    Connect members

    Draw straight members and assign moment-resisting, one-end-released or pin-ended behavior individually.

  3. 3

    Apply supports

    Use fixed, pinned, horizontal roller, vertical roller or custom restraints.

  4. 4

    Add structural loads

    Place nodal forces and moments or apply point and distributed loads along members.

  5. 5

    Assign stiffness

    Choose materials and custom or standard steel sections to define elastic modulus, area and moment of inertia.

  6. 6

    Run the analysis

    Check reactions and displacement before reviewing axial, shear and moment diagrams.

Start a blank structural model

Model definition

Nodes, supports, sections and structural loads

The workspace supports exact input without turning every common action into a table-first workflow.

Nodes and geometry

Place, drag, label and edit node coordinates. The model warns about disconnected nodes and crossing members that do not share a joint.

Supports and releases

Restrain horizontal translation, vertical translation and rotation using common support presets or custom degrees of freedom.

Materials and sections

Define elastic modulus, density, cross-sectional area and moment of inertia, or add a standard steel section from AISC, CISC, EN or UK catalogs to the project library.

Nodal loads

Apply global X and Y forces or a nodal moment at a selected structural joint.

Member loads

Apply concentrated, uniform, partial, triangular or trapezoidal loads using local or global directions.

Cases and combinations

Organize dead, live, wind, snow and other actions in named cases, then create user-defined factored combinations.

Structural self-weight

Generate distributed self-weight from the assigned material density and member area. For ideal truss analysis, replace span-applied self-weight with equivalent nodal loads.

Metric and imperial units

Work in metres and kilonewtons or feet and kips while retaining the underlying structural model.

Structural response

Reactions, displacement, axial force, shear and moment

Start by checking equilibrium and the deflected shape, then inspect the governing member forces and result stations.

R

Support reactions

Review horizontal force, vertical force, resultant force and restrained support moment.

Δ

Deflected shape

Inspect nodal translation, joint rotation and the displaced curve of frame members.

N

Axial-force diagram

Identify peak tension and compression in continuous, released and pin-ended members.

V

Shear-force diagram

Display member shear for moment-resisting, released and span-loaded pin-ended members.

M

Bending-moment diagram

Review end actions, internal peaks and the governing location along every member.

Calculation documentation

Detailed structural analysis PDF report

Create a structured frame or truss calculation package from the model you actually analyzed. The PDF connects the selected load case or combination to the model inputs, stiffness assumptions, solver checks and calculated response, so reviewers can follow the analysis without assembling screenshots and separate tables.

The report is intended for engineering calculation files, design review, project records and team handoff. Add a project number, preparer, checker and report-specific notes before export.

01

Analysis basis

Method, model scope, units, axes, sign conventions, degrees of freedom, assumptions and limitations.

02

Complete model inputs

All nodes, supports, materials, sections, members, end releases, loads, load cases, self-weight and combinations.

03

Solver and equilibrium checks

Stability status, active and restrained degrees of freedom, condition estimate, numerical residuals and warnings.

04

Engineering results

Reactions, nodal translations and rotations, member end actions, governing forces and individual member sheets with peak values and response diagrams.

05

Structural diagrams

Factored model, reaction, deflected-shape, axial-force, shear-force and bending-moment views where applicable.

Reproducible checks

Structural solver verification, generated from test evidence

The public Verification Centre connects closed-form reference equations to the exact production-solver results, tolerances and numerical diagnostics generated by the release test suite.

Current generated result All declared checks passed
12/12benchmark cases passed
87/87numerical checks passed

Current published evidence covers priority analytical beam, bar, member-release and coordinate-transformation cases, plus the worked four-panel Pratt truss benchmark. Additional frame, mixed-model and browser evidence will be added as those suites are completed.

Evidence generated July 26, 2026.

Explore the Verification Centre

Method and scope

Analysis method and assumptions

The calculator assembles a global stiffness matrix for two-dimensional frame elements and solves the restrained linear system for nodal displacements and reactions.

Included

  • Direct stiffness method
  • First-order linear-elastic response
  • Small-displacement behavior
  • Axial and Euler-Bernoulli flexural stiffness
  • Member-end moment releases
  • Static load cases and linear combinations

Not included

  • P-Delta or second-order effects
  • Geometric or material nonlinearity
  • Tension-only or compression-only members
  • Shear deformation
  • Buckling, modal or dynamic analysis
  • Code-based design or connection capacity

AI-assisted modeling · deterministic analysis

Describe the structure. Review the model. Then solve it.

Optimal AI translates an engineering request into real model operations—nodes, members, supports, loads, materials and sections—not a picture or a guessed calculation. It can also inspect the current model, explain warnings and help interpret the displayed response.

  • Preview firstSee the proposed geometry and exact change set before anything is applied.
  • You stay in controlAccept the proposal, revise the instruction or keep the existing model unchanged.
  • Solver-backed resultsReactions, forces and displacements come from the structural solver after you choose Run analysis.
Open Optimal AI in the workspace
Describe the model in plain language

“Create a two-storey, 6 m wide braced frame with fixed bases, 3 m storeys and a 20 kN roof load.”

  1. 1
    Model-aware proposal

    Optimal AI maps the request to editable structural entities and assignments.

  2. 2
    Visual preview and change list

    Review what will be added, changed or removed before applying it.

  3. 3
    Deterministic solve

    Run the same stiffness solver used for manually created models.

Clear responsibility boundaryAI assists with model creation and interpretation. The analysis engine calculates the structural response.

Engineering notes

2D structural analysis questions

This calculator is intended for preliminary analysis, learning and engineering review. Confirm the model assumptions, inputs and final design against the applicable codes and project requirements.

What structures can the 2D frame and truss calculator analyze?

The calculator analyzes plane frames, pin-jointed trusses, braced structures and mixed models. Moment-resisting frame members and pin-ended members can be combined in one workspace. Loads applied along pin-ended member spans can create local shear, bending and deflection.

Which analysis method does the calculator use?

It uses the direct stiffness method for first-order linear elastic analysis. Translational degrees of freedom are assembled at connected nodes, while rotational degrees of freedom are activated only where at least one member end transfers moment.

Can I drag nodes and edit a structure after drawing it?

Yes. Nodes can be dragged with grid snapping, and every selected node, member, support or load can be edited numerically in the properties inspector. The model is analyzed again whenever you choose Run analysis.

What results are included?

Results include support reactions, nodal translations and rotations, and member axial, shear and bending response. The canvas can display deflected shape and force diagrams for continuous and released members.

What is included in the structural analysis PDF report?

The PDF calculation report documents the analyzed model, supplied project details, analysis method, units and sign conventions, nodes, restraints, materials, sections, member connectivity and releases, applied loads, load cases, self-weight, combinations, solver diagnostics, equilibrium checks, reactions, displacements, member end actions, governing forces, structural diagrams and optional individual member summary sheets with peak values and local response diagrams.

Can frame and pin-ended members be combined in one model?

Yes. Moment-resisting frame members and pin-ended members can be combined in one model, allowing frames, trusses and braced structures to be analyzed in the same workspace.

Can the calculator analyze statically indeterminate structures?

Yes. The direct stiffness solver can analyze stable, statically determinate and indeterminate 2D models subject to the calculator assumptions and available member behavior.

Does the calculator support load cases, combinations and self-weight?

Yes. Loads can remain unassigned, be organized into named cases or categories, and be combined with user-defined factors. Structural self-weight can be generated from member area, assigned material density and a load-case multiplier.

Can the calculator perform axial-only truss analysis?

Yes. Assign pin-ended behavior to the truss members and apply loads at the joints. Under these conditions, the members reproduce the ideal axial tension-or-compression response of a pin-jointed truss. Loads applied directly along a member can create local shear and bending and are therefore not part of the ideal truss assumption.

Does the calculator include P-Delta or tension-only analysis?

No. The current solver performs first-order linear-elastic analysis. It does not include P-Delta effects, geometric or material nonlinearity, tension-only members, buckling, vibration or code-based capacity checks.

Is the 2D structural analysis software free?

Yes. Geometry, supports, ordinary loads, standard and custom section or material assignments, reactions and member-force diagrams are free. Anonymous visitors also receive three complete displacement-result previews. Load cases, combinations, self-weight, cloud saving, PDF reports, Optimal AI and project history depend on the account plan.

Continue the workflow

Beam CalculatorShear, moment, deflection and stress for single and continuous beams. Section PropertiesCalculate area, centroid and second moment of area for custom shapes. Steel Beam SizesBrowse and compare AISC and international structural sections. Structural Analysis DocumentationReview modeling inputs, units, supports, loads, sign conventions and result guidance.