In a parallel chord truss, which chord is typically in tension under loading?

In a parallel chord truss, which chord is typically in tension under loading?

• A. Top chord
• B. Horizontal member
• C. Bottom chord
• D. Diagonal member

Answer: (C)

When a parallel-chord truss carries vertical loads, the structure behaves like a series of triangles that convert those loads into axial forces in the members. The top chord tends to be pushed together, so it goes into compression, while the bottom chord is pulled apart across the span, putting it in tension. The diagonals and verticals mainly transfer shear and help keep the geometry stable, but the bottom chord is the member that resists being stretched as the truss bends under the load. This is why the bottom chord is typically in tension under loading.

When a parallel-chord truss carries vertical loads, the structure behaves like a series of triangles that convert those loads into axial forces in the members. The top chord tends to be pushed together, so it goes into compression, while the bottom chord is pulled apart across the span, putting it in tension. The diagonals and verticals mainly transfer shear and help keep the geometry stable, but the bottom chord is the member that resists being stretched as the truss bends under the load. This is why the bottom chord is typically in tension under loading.