Module 1 mechnaics - Shear Stress

Question 1

What is shear force and what formula is used to calculate it? What are the units of stress?

Answer 1

Shear stress is defined as the component of stress coplanar (90 degrees) with a material cross section

Question 2

What are three example questions that you could be asked that involve shear stress?

Answer 2

1. Single shear- area is equal to cross sectional area
2. a hole punch- the area is equal to the perimeter of the punch x the depth of the material.
3. Double shear- the area is equal to 2 x cross sectioanal area.

Question 3

A rectangular plate for a truss bridge is to be punched from 10mm sheet steel with a force of 60kN. During the punching operation two 25mm diameter holes are also punched. Find the shear stress if the plate has dimensions 150mm by 120mm.

1. find the area in shear first .
2. calculate stressn

Answer 3

1. perimeter of shape = 0.697m, thickness = 1 x10^-3, therefore shear area = 0.697 x 0.001 = 6.97 x 10^-3m²
2. 8.61 MPa

Question 4

A bolt is used to hold a coupling together. If the coupling takes a load of 10kN and the maximum allowable shear stress is 30MPa, determine the minimum diameter of the bolt.

Answer 4

Don’t forget to use 2x cross sectional area in your calculations where the diameter of the bolt is the only unknown.

Answer= 14.57mm