Design assumptions for riveted joints in structural steel Which of the following is a standard assumption used when designing riveted joints?

Introduction / Context:
Riveted (and similarly bolted) joint design uses simplifying assumptions to make group-capacity checks tractable. Understanding these assumptions helps interpret formulas for shear and bearing capacities and spacing rules.

Given Data / Assumptions:

• Group of rivets transferring load between plates.
• Working-stress method context with classic detailing rules.
• Uniform load-sharing is a common simplifying hypothesis.

Concept / Approach:
For concentric loads on compact patterns, designers typically assume uniform shear among all rivets, and approximately uniform bearing stress at the interface. These assumptions are conservative for many practical joints and enable straightforward sizing.

Step-by-Step Solution:
State the core assumption → uniform load distribution among the rivets.Use this to compute number of rivets = demand / single-rivet strength.Verify bearing and edge-distance checks separately.

Verification / Alternative check:
For eccentric or prying-loaded joints, refined analyses distribute load non-uniformly (polar moment method), but the uniformity assumption remains the baseline for concentric loading.

Why Other Options Are Wrong:

• Neglecting bearing in rivet (b) is unsafe; bearing is explicitly checked.
• (c) and (d) are not standard design assumptions for capacity or detailing.
• (e) Friction is not relied upon in ordinary riveted joints unless specifically designed as a friction/grip connection.

Common Pitfalls:
Applying uniform distribution to eccentric joints without additional checks leads to underestimation of peak rivet forces.

Final Answer:
Load is uniformly distributed among all the rivets in the group