- See Article - Beam Design Formulas
Diagram Symbols
Bending moment diagram (BMD) - Used to determine the bending moment at a given point of a structural element. The diagram can help determine the type, size, and material of a member in a structure so that a given set of loads can be supported without structural failure.
Free body diagram (FBD) - Used to visualize the applied forces, moments, and resulting reactions on a structure in a given condition.
Shear force diagram (SFD) - Used to determine the shear force at a given point of a structural element. The diagram can help determine the type, size, and material of a member in a structure so that a given set of loads can be supported without structural failure.
Uniformly distributed load (UDL) - A load that is distributed evenly across the entire length of the support area.
Two Span Continuous Beam - Equal Spans, Two Equal Concentrated Loads Symmetrically Placed formulas |
||
|
\( R_1 \;=\; V_1 \;=\; R_3 \;=\; V_3 \;=\; \dfrac{ 5\cdot P }{ 16 }\) \( R_2 \;=\; 2V_2 \;=\; \dfrac{ 11\cdot P }{ 8 }\) \( V_2 \;=\; P - R_1 \;=\; \dfrac{ 11\cdot P }{ 16 }\) \( V_{max} \;=\; V_2 \) \( M_1 \;=\; -\; \dfrac{ 3\cdot P\cdot L }{ 16 } \) \( M_2 \;=\; \dfrac{ 5\cdot P\cdot L }{ 32 } \) \( M_x \; ( x < \frac{L}{2} ) \;=\; R_1\cdot x \) |
||
| Symbol | English | Metric |
| \( x \) = horizontal distance from reaction to point on beam | \(in\) | \(mm\) |
| \( M \) = maximum bending moment | \(lbf-in\) | \(N-mm\) |
| \( V \) = maximum shear force | \(lbf\) | \(N\) |
| \( R \) = reaction load at bearing point | \(lbf\) | \(N\) |
| \( L \) = span length under consideration | \(in\) | \(mm\) |
| \( P \) = total consideration load | \(lbf\) | \(N\) |
