- What is the method to reduce stress concentration?
Although it is not possible to completely eliminate the effect of stress concentration,there are various methods to reduce stress concentration.This can be achieved by providing a specific geometric shape to the component.
(A) ADDITIONAL NOTCHES AND HOLES IN TENSION MEMBER:
The severity of stress concentration can be reduced by three methods:
(i)Use of multiple notches.
(ii) Drilling additional holes.
(iii)Removal of undesired material.
(B)FILLET RADIUS, UNDERCUTTING & NOTCH for member in Bending:
Ball bearings,gears or pulleys are mounted against this shoulder.The shoulder creates a change in cross-section.of the shaft,which results in stress concentration.
There are three methods to reduce stress concentration at the base of this shoulder:
(i)By providing fillet radius at shoulder.
(ii)By undercutting the should.
(iii)By additional notch at the top of shoulder.
(C) DRILLING ADDITIONAL HOLES FOR SHAFT:
A transmission shaft with a keyway is shown in figure(a). The keyway is a discontinuity and results in stress concentration at the corners of the keyway,therefore holes are drilled to minimise the stress concentration at the corners of keyway as shown in figure (b).
(D) REDUCTION OF STRESS CONCENTRATION IN THRILLED MEMBERS:
A threaded component is shown in figure (a).There are three methods to reduce stress concentration.
(i) Undercutting as shown in figure (b).
(ii) Reduction in Shank Diameter as shown in figure (c).
There are the number of means by which engineers reduce the likelihood of stress concentration occuring through careful design of components.These also include:
Avoiding sharp corners amd only rounded corners with maximum radii.
Sandling and polishing surfaces to remove any notches or defects that occurr during forming and processing.
Lowering the stiffness of straight load-bearing segments.
Placing notches and threads in low-stress areas.
To know more about ‘stress concentration',please go through the following links:
https://mechomotive.com/cross-section-variationstress-conc-study/