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Best SFD_BMD Calculator

ProBeam — Advanced Structural Analysis
Solve Mode: — Auto FEM · Hinge-aware
Tip: Drag to move · Double-tap/click to edit · Del to remove selected · Negative force = upward · Ctrl+Z Undo · Ctrl+Y Redo
Reactions & Results
Diagrams
SHEAR FORCE DIAGRAM (SFD)
V(x)
BENDING MOMENT DIAGRAM (BMD)
M(x)
DEFLECTION / ELASTIC CURVE
δ(x)
Symbolic Equations

Piecewise V(x), M(x)

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Edit Element

ProBeam — User Guide

Full structural analysis of any 1D beam using the Direct Stiffness Method (FEM), Euler-Bernoulli beam elements. Handles determinate and indeterminate beams exactly.

Sign Convention

  • Downward loads: positive. Upward loads: negative.
  • Sagging moment (concave up): positive (+). Hogging: negative (−).
  • Reactions shown as ↑ upward or ↓ downward.

Supports

  • Pin — Fy (and Fx).
  • Roller — Fy only.
  • Fixed — Fy + moment M.

Load Types

  • Point Load — Concentrated force. Negative = upward.
  • UDL — Uniform. Negative = upward.
  • UVL — Zero→peak at end.
  • Tri ◁ — Peak at start, zero at end.
  • Tri ▷ — Zero at start, peak at end.
  • Trapezoid — Linear variation.
  • Moment — Applied couple CW or CCW.
  • Hinge ◉ — Internal hinge: bending moment = 0, rotation free, shear & deflection continuous.

Features

  • SFD, BMD, Elastic Curve (Deflection)
  • Point of Contraflexure (marked on beam & BMD)
  • Max Shear / Max Moment auto-labelled
  • Reaction values displayed on beam
  • Undo/Redo history (Ctrl+Z / Ctrl+Y)
  • Save/Load project as JSON
  • Export text report
  • Snap control (0.1 / 0.5 / 1m)

Keyboard

  • Delete/Backspace — Remove selected
  • Escape — Deselect / close panel
  • Ctrl+Z — Undo
  • Ctrl+Y / Ctrl+Shift+Z — Redo

Analysis Report