Question

A lap joint with two plates fastened together by four rivets is to be used as connection in a vertical structure to hold and mount projector in our classroom. What are the necessary things to consider in designing this?

Answer 1

The required things for good connection :-

1》It should be rigid enough to avoid fluctuating stresss which may cause fatigue failure.

2》It should be such that there should be least possible weakening of the parts of joint.

3》It should be such that easily installed, inspected and maintained.

4》Length of joint should be as small as possible.

5》 The arrangement should satisfy the pitch and edge requirements

6》The center line of all joints meeting at a joint should be coinside at one point only otherwise the joint will twist out of its position.

7》 Gross diameter = nominal diameter + 1.5mm , d<= 25mm

8》 Gross diameter = nominal diameter + 2.0mm , d>= 25mm

9》 minimum pitch = 2.5 ×( nominal diameter)

10》 minimum edge distance = 1.5 d ( hand cut) and 1.7 d ( machine cut)

11》 maximum edge distance = 40mm + 4t , t= thickness of thinner plate.