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Internal forces in structural members2D

Determinate-frame diagrams

Expose and verify normal force, shear force, and bending moment using independent isolated-body calculations.

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Interactive engineering simulation

Determinate Frame Internal-Force Diagrams

Display N, V, and M for both members of a rigid determinate frame.

Tension-positive N · sagging-positive M
Sign convention: positive tension. On the left cut face, positive shear acts downward and positive moment counterclockwise; arrows reverse on the right face. Downward distributed load is positive, so dV/dx=w(x)dV/dx=-w(x) and dM/dx=V(x)dM/dx=V(x).
Rigid corner B · pin A · roller C
Beam BC normal NkN
Beam BC shear VkN
Beam BC moment MkN·m
Column AB normal NkN
Column AB shear VkN
Column AB moment MkN·m
Aₓ
-8.00 kN
Aᵧ
8.00 kN
Cᵧ
12.00 kN
Force residual
0.00e+0
Moment residual
0.00e+0
Frame span
10 m
m
618

Drag for exploration or enter an exact value. Press Enter to apply; Escape restores the current value.

Column height
5.0 m
m
2.010.0

Drag for exploration or enter an exact value. Press Enter to apply; Escape restores the current value.

Vertical beam load
20 kN
kN
260

Drag for exploration or enter an exact value. Press Enter to apply; Escape restores the current value.

Horizontal joint load
8 kN
kN
030

Drag for exploration or enter an exact value. Press Enter to apply; Escape restores the current value.

Vertical-load position
4.00 m
m
0.509.50

Drag for exploration or enter an exact value. Press Enter to apply; Escape restores the current value.

dVdx=w(x)\frac{dV}{dx}=-w(x)
dMdx=V(x)\frac{dM}{dx}=V(x)
Model scope and verification

Use the displayed units and idealizations, then verify the governing balance or compatibility equation before interpreting the result.