Engineering › Materials ›
Shear Stress
An introduction Shear Stress, Modulus of Rigidity and Strain Energy.
Contents
Shear Stress
If the applied load consists of two equal and opposite parallel forces which do not share the same line of action, then there will be a tendency for one part of the body to slide over, or shear from the other part. In the figure below, if the section LM is parallel to the forces and has an area A, then the average Shear StressMISSING IMAGE!
23287/Shear-Stress-0001.png cannot be found in /users/23287/Shear-Stress-0001.png. Please contact the submission author.
Complementary Shear Stress.
A,B,C,D is a small rectangular element whose sides are x, y and z which are perpendicular to the figure. A Shear Stress S acts on the planes A,B and C,DMISSING IMAGE!
23287/Shear-Stress-0002.png cannot be found in /users/23287/Shear-Stress-0002.png. Please contact the submission author.
MISSING IMAGE!
23287/Shear-Stress-x.png cannot be found in /users/23287/Shear-Stress-x.png. Please contact the submission author.
Example:
[imperial]
Example - Shear stress on shaft bolts
Problem
A Flange Coupling which joins two sections of a Shaft is required to transmit 250 h.p. at 1000 r.p.m. If six bolts are used on a pitch circle of 6 ins. find the diameter of the bolts. The allowable mean Shear Stress is 5 tons/in2.
Workings
Torque to be transmitted s given by:
If d is the diameter of a bolt the load carried by one bolt is:
Multiplying by the number of bolts and their radius arm, the torque carried is:
Solution
Diameter of bolt, 
Shear Strain
The distortion produced by Shear Stress on an element or Rectangular Block is shown in the following diagram.MISSING IMAGE!
23287/Shear-Stress-0004.png cannot be found in /users/23287/Shear-Stress-0004.png. Please contact the submission author.
The Modulus Of Rigidity
For Elastic materials it is found that within certain limits, Shear Strain is proportional to the Shear Stress producing it. The RatioStrain Energy
Within the limits of proportionality Strain is proportional to Stress and: Strain Energy (U) = Work done in Straining. For a gradually applied stress the work done is shown on the diagram as the shaded area.MISSING IMAGE!
23287/Shear-Stress-0005.png cannot be found in /users/23287/Shear-Stress-0005.png. Please contact the submission author.