StructLab.tech Hub

Civil Engineering Mechanics Suite
Dedicated to Civil Engineering Bachelor Students

Structural Mechanics,
Interactive & Exact.

A unified suite of lightweight, browser-native civil engineering tools. Solve closed-form Euler-Bernoulli beams, perform Direct Stiffness frame analyses, and compute CAD cross-section properties in seconds.

● 100% Free & Client-Side ● Analytical Closed-Form Solvers ● KaTeX Step-by-Step Proofs ● Tension-Fiber Moments ($M$)
Choose a Calculator See Coursework Flow

Core Structural Analysis Apps

Three specialized calculators designed to align directly with Statics, Mechanics of Materials, and Structural Analysis coursework.

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beam.structlab.tech

Beam Calculator

Analytical Euler-Bernoulli Solver

Exact closed-form analytical solutions for statically determinate and indeterminate beams with multi-supports, settlements, and internal hinges.

✓ Tension-Fiber Moment: Positive $M(x)$ sagging drawn downwards (*włókna rozciągane*).
✓ Shear & Deflection: $T(x)$ distribution, downward deflection $w(x)$ in mm.
✓ Step-by-Step KaTeX: Full static equilibrium ($\sum F_z=0, \sum M=0$) derivation sheets.
✓ 8 Benchmark Presets: Overhanging, continuous, propped cantilever beams.
Launch Beam App beam.structlab.tech
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frame.structlab.tech

Frame Calculator

Direct Stiffness Method (DSM)

Interactive canvas CAD tool for modeling arbitrary 2D frames, continuous portal frames, and trusses using the direct stiffness matrix formulation.

✓ Internal Forces ($N, T, M$): Normal axial forces, transverse shear, and bending moments.
✓ Member Hinges & Pins: Clamped, pinned, and roller supports with node releases.
✓ Interactive Canvas: Click-to-draw nodes and elements with 0.5m grid snapping.
✓ Bilingual UI (EN/PL): 1-click toggle between English and Polish civil notation.
Launch Frame App frame.structlab.tech
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section.structlab.tech

Section Calculator

CAD Geometric & Inelastic Solver

Calculate, visualize, and analyze cross-sectional geometric properties for standard steel/concrete profiles and arbitrary CAD polygons.

✓ Area & Inertia: Centroid $(\bar{x}, \bar{y})$, reference $I_x, I_y$, product $I_{xy}$ via Green's Theorem.
✓ Principal Axes: Maximum $I_1$, minimum $I_2$, and rotation angle $\theta_p$.
✓ Neutral Axes: Elastic Neutral Axis (ENA) and Plastic Neutral Axis (PNA).
✓ Core of Section (Kern): Exact elastic kern boundary mapping for eccentric compression.
Launch Section App section.structlab.tech
Academic Workflow

How the 3 Apps Complete Your Coursework

From cross-section geometry to full structural frame response, the StructLab triad mirrors the standard civil engineering design pipeline.

1

Section Geometry

Use SecCalc to define your custom steel/concrete profile. Extract the Cross-Sectional Area $A$, Moment of Inertia $I_y, I_z$, and Elastic Section Modulus $W$.

Output: A, I_y, I_z, W_el, W_pl
2

Internal Force Analysis

Input member stiffness $EI$ and $EA$ into the Beam or Frame Calculator. Solve statically determinate or indeterminate systems for $N(x), T(x), M(x)$.

Output: M_max, T_max, N_max, Reactions
3

Stress & Capacity Check

Combine results to verify Eurocode / AISC normal stress limits and serviceability deflection criteria:

$$\sigma = \frac{N}{A} \pm \frac{M}{W} \le f_y, \quad w_{\max} \le \frac{L}{250}$$
Output: Stress check & Deflection criteria
PX WUT / PW
Academic Research & Computational Mechanics

Pengyuan Xia

PhD Student · Warsaw University of Technology (Politechnika Warszawska)

Developed StructLab as a free, rigorous, and interactive open-source computational platform for civil engineering students, researchers, and structural mechanics educators. Have feedback, bug reports, or collaboration inquiries? Feel free to reach out.

pengyuan.xia.dokt@pw.edu.pl GitHub (@PengyuanXia) Buy me a coffee