Question

What is shear lag effect?

(a) the phenomenon of non uniform bending stress not due to influence of shear strain induced on bending stresses in flanges

(b) the phenomenon of uniform bending stress not due to influence of shear strain induced on bending stresses in flanges

(c) the phenomenon of uniform bending stress due to influence of shear strain induced on bending stresses in flanges

(d) the phenomenon of non uniform bending stress due to influence of shear strain induced on bending stresses in flanges

This question was posed to me during a job interview.

I want to ask this question from Design Strength of Laterally Supported Beams in chapter Design of Beams of Design of Steel Structures

Answer 1

The correct answer is (d) the phenomenon of non uniform bending stress due to influence of shear strain induced on bending stresses in flanges

The best explanation: The shear strain induced influences bending stresses in flanges and causes sections to warp. This consequently modifies the bending stresses determined by simple bending theory and results in higher stresses near junction of web to flange elements with stress dropping as distance from beam web increases. The resultant stress distribution across flange is therefore non uniform and this phenomenon is known as shear lag.