Consider the following statements related to principles of design of connections: 1.The centre of gravity of bolts should coincide with the centre of gravity of the connected members. 2.The length of connection should be kept as small as possible. Which of the above statements is/are correct?
- A1 only
- B2 only
- CBoth 1 and 2Correct
- DNeither 1 nor 2
Solution
Concept
Good connections avoid eccentricity and are kept compact.
Step-by-step solution
1. If the CG of the bolts matches the CG of the member, there is no eccentric moment, so statement 1 is correct. 2. A short connection saves gusset plate material, and in long joints the bolts carry unequal loads, so strength reduces (long joint factor). So statement 2 is correct. 3. Both statements are correct.
Explanation
When the bolt group CG lines up with the member CG, the load passes without extra bending. A short connection is cheaper and makes the bolts share load evenly. So both statements are correct.
Why the other options are wrong
A and B pick only one correct statement. D rejects both, but both are true.
Shortcut
No eccentricity and compact joint are both basic rules of connection design.
Common mistake
Thinking a longer connection is always stronger. In fact, in long joints the end bolts get overloaded.
Correct answer: C) Both 1 and 2