Question

What is the value of partial factor of safety for material α for preliminary design for angle section as per IS code for three bolts in connection?

(a) 0.6

(b) 0.7

(c) 0.8

(d) 1.0

The question was asked in a job interview.

The question is from Angles Under Tension and Factors affecting Strength topic in section Design of Tension Members of Design of Steel Structures

Answer 1

The correct answer is (b) 0.7

Best explanation: As per IS code, the equation for preliminary design of angle tension member  with partial factor of safety for material is given by Tdn = αAnfy/γm1, where α = 0.6 for one or two bolts, 0.7 for two bolts, 0.8 for four or more bolts in the end connection or equivalent weld length.