Fast web-based analysis and design for steel and concrete structures.
Build 2D frames and trusses or full 3D frames with shell slabs and walls. Generate wind loads, run static, buckling, modal, response-spectrum and moving-vehicle analysis, check steel and reinforced-concrete members to Eurocode, and carry a reviewable model into your next engineering tool.
↳ Start with a sample model or draw your own frame in the browser.
FRAME STUDY · 2D● MODEL READY
ACTIVE VIEWThree-storey frame
Loads, supports, bending-moment shading and the sway shape of a two-bay frame, from one linear static analysis.
ACTIVE VIEWFrame with shell slabs
Beams, columns and four-node shell slabs in one 3D model, with smooth contours of slab moments mx and my.
ACTIVE VIEWWind pressure on a building
Wind speed and terrain give the velocity profile and zone pressures D, E, F, G, H. Apply them to frames or cladding panels.
ACTIVE VIEWUtilisation by member
Section class, bending, buckling, lateral-torsional and combined checks for every load case and combination.
ACTIVE VIEWRequired reinforcement
Flexural reinforcement from the ultimate moment, with strain and force equilibrium for beams, columns, slabs and walls.
01 — ENGINEERING, MADE VISIBLE
2D Frame workspace
3 analysis methods
EC3 Steel member checks
RTD Robot Structural Analysis exchange
Model. Analyze. Design and review.
FaxinaX brings structural modelling, wind loading, finite-element analysis, result inspection, and steel and concrete member design into one browser-based workflow.
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Build in 2D or 3D
Draw 2D frames and axial-only trusses, or work in a 3D space frame with beams, columns and four-node shell slabs and walls. Assign steel database, rectangular concrete or manual sections, supports, releases and loads in a full-width model canvas, and open extra canvas windows to compare views side by side.
SNAP · SHELLS · CANVAS WINDOWS · SAVED MODELS
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Generate the actions
Create named load cases and combinations, and generate wind loads to EN 1991-4 from wind speed, terrain and building geometry. Apply the pressures to a 2D frame or to 3D cladding panels that pass their load to the members, and define moving vehicles that travel along a route.
WIND · CLADDING · COMBINATIONS · VEHICLES
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Choose the analysis
Run linear static analysis in 2D and 3D, linear buckling, natural frequencies with mode shapes, and response-spectrum analysis with SRSS or CQC. Run a load case that contains a moving vehicle to see the animated response and the influence line from the same analysis.
Check steel members to Eurocode 3 for every load case and combination, with biaxial bending, buckling and warping torsion in 3D. Design reinforced-concrete beams, columns, slabs and walls to Eurocode 2, including shell reinforcement.
EC3 · EC2 · UTILISATION · REINFORCEMENT
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Read the results
Show diagrams, smooth contours of displacement, force and shell moments, and reactions on the canvas. Keep the analysis output hidden until you need it, then read nodal displacements, member extrema and the equilibrium check, with each window showing its own result.
CONTOURS · DIAGRAMS · RESULT CHECK
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Share and exchange
Import 2D centre-lines from AutoCAD DXF. Export 2D and 3D models to Robot Structural Analysis RTD, SAP2000 S2K or DXF, and download PDF reports for the analysis and the steel design check.
RTD · S2K · DXF · PDF REPORT
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Start from existing geometry. Import 2D centre-lines from AutoCAD DXF. Export model geometry and supported data to Robot Structural Analysis RTD, SAP2000 S2K, or AutoCAD DXF.
Move from an editable structural model to traceable loads, analysis results, design checks, and exchange files in one workspace.
Build connected models with fewer edits
Draw 2D frames and axial-only trusses with snapping and automatic node creation. Existing nodes lying on a member connect in the analysis while the original member remains intact on screen. Subdivide explicitly into a chosen number of parts or at existing nodes when you want separate members.
AUTOMATIC CONNECTIVITY · OPTIONAL SUBDIVISION
Represent the stiffness you intend
Assign properties per member using steel database profiles, rectangular concrete sections, or manual analysis properties. Edit E, G, area, inertia, shear area, and mass density. Choose frame or truss behavior, end releases, rotated restraints, and spring supports for Ux, Uy, and rotation about z.
SPRINGS IN kN/m & kNm/rad · SHEAR DEFORMATION OPTION
Keep actions organized and inspectable
Manage named load cases, nodal forces and moments, and uniform or point member loads. Generate self-weight from member density and area, with numerical load values displayed in the webapp for you to inspect. This transparent calculation makes assumptions easier to check, supports reliable modelling, and speeds up load preparation and review. Build manual combinations or automatic ULS persistent/transient combinations, including permanent-only cases. Apply loads to member ranges through concise text commands.
SELF-WEIGHT · CASES · COMBINATIONS · RANGE ENTRY
Follow forces through the structure
Solve 2D linear-elastic, first-order models and inspect signed axial-force, shear-force, bending-moment, and displacement diagrams. Review nodal movements, support reactions, and member maxima and minima for the selected case or combination. Colour the members with displacement or force contours, and use Normalize to keep the deformed shape and force diagrams readable even when the real values are very small. Combinations of any number of load cases are superposed member by member.
Calculate natural frequencies and normalized mode shapes with member mass and selected load-to-mass sources. Animate modes and review participation. Use supported EN 1998 spectrum options with SRSS or CQC modal combination for global-X response-spectrum results and an inspectable spectrum curve.
MASS SOURCES · MODE ANIMATION · SPECTRUM CURVES
Turn analysis into member checks
Use static member actions for Eurocode 3 checks on assigned database steel sections. Define steel grades, effective buckling lengths, and intermediate restraints. For lateral-torsional buckling, choose how to enter the input: define brace points, give a critical length, or give Mcr directly. With brace points, FaxinaX reads the bending-moment diagram of each braced segment, selects the loading case and the moment factor for you, and shows what it selected, so you no longer enter them by hand. Deflection limits are checked relative to the line between the member ends. Edit groups together, inspect interaction factors, and see the maximum utilization ratio as a colour contour with the values printed on the model, in the app and in the PDF report.
EC3 · AUTOMATIC LTB CASE AND MOMENT FACTOR · MEMBER GROUPS · UTILIZATION CONTOUR · PDF
Edit comfortably at every scale
The drawing surface adapts to the structural model, with zoom, pan, fit, and full-screen views. Expand node, member, and load tables for larger models. Use Ctrl+Z and Ctrl+Y to undo and redo, Ctrl+S to save, and Esc to clear selection or leave an unfinished drawing action.
Load frame, beam, portal, and bridge or tower examples, or begin with imported DXF centre-lines. Save and update model inputs in your browser, including member properties, load cases, combinations, and supports. Saved models belong to the browser and site address used to save them.
SAMPLE MODELS · DXF IMPORT · BROWSER STORAGE
Catch modelling mistakes before you rely on results
After every analysis FaxinaX shows a result check, even when it reads 0 errors and 0 warnings. It flags a mechanism and tells you why (not enough supports, supports that cannot stop rigid-body motion, or too many releases), huge displacements, isolated nodes or disconnected parts, deflection above span/50, and values that suggest wrong units. It also reminds you where self-weight is generated automatically so it is not added twice.
For every load case and combination, support reactions are compared with the applied loads: ΣFx, ΣFy and ΣM, including self-weight. For a self-weight case the total weight is compared with the total vertical reaction. A failed balance is reported as an error, so a wrong result is noticed in seconds instead of during review.
ΣFx · ΣFy · ΣM · WEIGHT = REACTION
Reports you can hand over
Export an FEA results report with model assumptions (general ones once, member-specific ones with the members they apply to), loads and combinations, nodal results, deformation and force diagrams, and contours drawn in the same style as the workspace. The report ends with a model check section listing errors, warnings, and the equilibrium check for each result. The steel design report adds the utilization contour with the ratio on each member.
A compiled C++ FEM core and sparse numerical solvers reduce analysis work for larger 2D models. Connectivity warnings help identify unused nodes and disconnected groups. The theory page documents formulations, assumptions, and analytical comparison cases so you can understand the calculation behind the display.
COMPILED COMPUTATION · SPARSE SOLVERS · THEORY
Find a safe, economical structure
In the 3D structure workspace, the optimisation toolbox checks every steel member against EN 1993-1-1 and every concrete member against EN 1992-1-1, for all load cases and combinations. It enlarges members that fail and reduces sections where there is room, keeping a change only if the structure still complies and the price or embodied CO₂e falls. Set a maximum utilisation of 1.00 or lower and an optional price limit, or fix the sections you need and let FaxinaX size the rest. If you leave the sections to FaxinaX, it suggests the section input that reproduces the result. Volume, mass, price and CO₂e are shown for 2D and 3D models, calculated from your own unit prices and emission factors.
EN 1993-1-1 · EN 1992-1-1 · UTILISATION ≤ 1.00 · PRICE LIMIT · EMBODIED CO₂e
See the self-weight. Check the numbers.
Carry the model into Robot with explicit member loads that make self-weight easier to inspect and compare.
Transparent self-weight, from the webapp to Robot
See the numerical values of automatically generated self-weight directly in FaxinaX before you export. Check each member’s load against its density and section area, and review updated values when those properties change. Clear, visible inputs make self-weight easier to understand and verify, supporting reliable modelling with faster preparation and fewer repetitive calculations.
FaxinaX calculates each member’s self-weight from its mass density and cross-sectional area, then exports it to Robot as an equivalent downward uniform member load. The numerical load intensity is available in Robot’s load definition, so you can check the values applied to individual members.
Robot’s native self-weight command does not automatically present self-weight as these explicit uniform member-load entries. To inspect equivalent values that way using Robot alone, you would otherwise calculate and enter the uniform loads yourself. FaxinaX does that preparation for you, reducing repetitive input and helping you spot an incorrect density, section area, or self-weight definition before you rely on the results.
The RTD export also transfers supported member sections and materials, native truss behavior, restraints and springs, end releases, named load cases, and linear load combinations. Database steel sections retain their profile geometry when the matching catalogue is available in Robot.
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Continue in the tools you use. Export a native Robot RTD, a supported SAP2000 S2K model, or an AutoCAD DXF drawing. Import DXF centre-line geometry to begin modelling. Review units, axes, section properties, and supported data in the receiving program; SAP2000 spring export is currently unsupported.
Review force values along members, signed results, nodal movements, and reactions with the active load case or combination.
01 / MOMENT · kN·m02 / DEFLECTION · mm
From geometry to engineering review.
Keep model inputs, analysis cases, response plots, and design checks together so each result can be traced back to its assumptions.
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Choose a workspace and model
Use the 2D frame or 3D structure workspace. Draw members with automatic node creation, load a sample or saved model, or import DXF centre-lines. Assign materials, sections, releases, and supports.
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Define actions and analyze
Create named load cases and manual or automatic ULS persistent/transient combinations. Generate self-weight from section area and material density when wanted, or enter nodal and member loads; live-load category factors are available for combination generation. Generate wind loads, then run static, buckling, modal, response-spectrum or moving-vehicle analysis in 2D or 3D.
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Inspect, design, and export
Read the result check, then review signed force and displacement diagrams, nodal results, and member maxima and minima. Use the results for EC3 steel and EC2 concrete design, then download the FEA or steel design PDF report or export RTD, S2K, and DXF files.
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Need step-by-step help? The guide explains every step of this workflow, from importing geometry to reading the result check and exporting reports.
ENGINEERING REVIEWResults should be independently reviewed by a qualified structural engineer before use in design or construction. Analysis output depends on the assumptions, restraints, loads, and properties entered.
See how the solver works.
Understand the finite-element formulation, the assumptions behind each analysis type, how results are checked against analytical solutions, and how to judge whether an answer makes sense.
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Element and global equations
Each 2D frame node has horizontal and vertical translations and an in-plane rotation. Element stiffness matrices are transformed to global axes, assembled, and solved with the selected restraints.
STATIC EQUILIBRIUM · Kd = F · SHEAR OPTION
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Modal analysis
The modal solver obtains natural frequencies and mode shapes from the structural mass and stiffness matrices. Mode shapes can be inspected and animated in the workspace.
2D MODAL · NATURAL FREQUENCIES
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Compare with analytical cases
Benchmark examples compare solver responses with closed-form beam solutions and check global force and moment equilibrium. The same equilibrium check runs on your own model for each load case and combination. Verification is a useful independent cross-check, not a substitute for reviewing each project model.
Explore the detailed theory and verification page. Read the equations, solver assumptions, modal and spectrum methods, benchmark cases, hand-check formulas, common modelling mistakes, and the limits of a first-order analysis.
This release presents 2D frame and truss modelling with static, modal, and global-X response-spectrum analysis. Analysis choices may depend on deployment settings.
Built to make structural analysis easier to follow.
FaxinaX is a browser-based 2D frame analysis and steel member design workspace developed by Phealy Thourk. It combines 2D frame and truss modelling, static and modal analysis, response-spectrum tools, and steel member checks.
The software is an engineering aid, not a replacement for professional judgment or independent verification.
FaxinaX supports 2D linear-elastic frames and axial-only trusses with static, modal, and global-X response-spectrum analysis. Use static results for displacements, reactions, member forces, and supported steel checks; use modal and spectrum tools to study dynamic response.
Can I exchange models with other software?+
Import 2D centre-line geometry from DXF. Export model geometry and applicable model data to Robot Structural Analysis RTD or SAP2000 S2K, and create AutoCAD DXF drawings.
How does FaxinaX help me find mistakes in my model?+
Each analysis ends with a result check: mechanisms, isolated parts, huge displacements, deflection above span/50, suspicious units, and a global equilibrium test of reactions against loads, including self-weight. The same checks are written into the FEA results report. They support, but do not replace, your own review.
Can FaxinaX help me find an economical section layout?+
Yes, in the 3D structure workspace. The optimisation toolbox keeps only designs that pass the steel and concrete checks for every load case and combination, and that respect your maximum utilisation and any price limit. Sections you fix are kept, and the toolbox suggests the section input for the rest. Prices and CO₂e are estimates based on the unit prices and emission factors you enter. The result is a starting point: the responsible engineer must still review the design, its assumptions, and any requirement the checks do not cover.
Does a design check replace engineering review?+
No. The engineer responsible must verify assumptions, inputs, applicable design requirements, and results independently.
How does the trial work?+
Create an account in FaxinaX to start the 7-day trial. The application shows the subscription and KHQR instructions after the trial.