Comparison between rigid frames and trusses

Trusses

Rigid frames

• Joints are considered as having friction less pins in trusses with no moments at the member ends.
• The forces in trusses are only axial. Due to this members are equally stressed throughout their cross-section.

• The design of a member in case of a truss is economical.

• In rigid frames, the members are rigidly connected having appreciable moments at the member ends.
• Due to bending moments, the fibers away from the neutral axis have maximum stresses and fibers close to the neutral axis have less stress.
• The design of rigid frame member is less economical as compared to trusses.