Question

In a truss it is assumed that the members are joined by

• A. Rough pins
• B. Smooth pins
• C. Either of them
• D. Neither of them

Hint:

In ideal truss analysis, joints are assumed to be frictionless so that members carry only axial tension or compression.

Answer 1

The Correct Option is B

Step 1: Understanding the ideal truss assumption.
In the analysis of trusses, certain ideal assumptions are made to simplify calculations. One key assumption is related to the nature of joints between members.
Step 2: Nature of joints in a truss.
Truss members are assumed to be connected by smooth pin joints.
Smooth pins allow rotation but do not resist moments, ensuring that only axial forces (tension or compression) act in the members.
Step 3: Analysis of options.
(A) Rough pins: Incorrect, because rough pins would resist rotation and introduce moments.
(B) Smooth pins: Correct, as this assumption ensures members carry only axial forces.
(C) Either of them: Incorrect, since the assumption is specific to smooth pins.
(D) Neither of them: Incorrect, as pin joints are essential to truss behavior.
Step 4: Conclusion.
Hence, in a truss, members are assumed to be joined by smooth pins.