Question

Two plates of 12mm and 16mm thickness are to be joined by groove weld. The joint is subjected to factored tensile load of 400kN. Due to some reasons the effective length of weld that could be provided was 150mm only. What is the safety of joint if single-V groove weld is provided?

(a) Safe

(b) Unsafe

(c) Unsafe, but adequate

(d) Safe, but adequate

This question was posed to me in a national level competition.

I'm obligated to ask this question of Design of Welds topic in section Welded Connections of Design of Steel Structures

Answer 1

Right choice is (b) Unsafe

Best explanation: Lw = 150mm, Throat thickness, te = 5×12/8 = 7.5 mm

Strength of weld = Lwtefy/1.25 = 150×7.5x250x10^-3/1.25 = 225kN < 400kN. Therefore joint is unsafe and inadequate.