MCQs on Welded Joints Subjected to Bending Moments
1 - Question
The following bracket is welded to the vertical column. The joint undergoes torsional stresses.
a) True
b) False
View Answer
Answer: b
Explanation: This joint undergoes bending stresses but not torsional stresses.
2 - Question
A bracket is shown welded to a vertical column by means of two fillet welds. The bending stress induced in the welds can be given by
a) My/I
b) 2My/I
c) My/2I
d) None of the listed
View Answer
Answer: a
Explanation: Formula.
3 - Question
Calculate the moment of inertia about the axis parallel to welds and shift it to CG by considering thickness of welds t.
a) tᵌ+2000t
b) None of the listed
c) 250000 t
d) 125000 t
View Answer
Answer: c
Explanation: I=[50tᵌ/12 + (50t)x50² ] x 2, ignoring tᵌ term.
4 - Question
Find the bending stress in the top weld is if thickness of weld is t. Given P=15kN and e=120mm.
a) 230/t
b) 360/t
c) 200/t
d) None of the listed
View Answer
Answer: b
Explanation: σ=My/I or M=15000×120, y=50 and I=250000t.
5 - Question
Find the thickness of the weld is if allowable shear stress in the welds is 70N/mm². Given P=15kN and e=120mm.
a) None of the listed
b) 3.35mm
c) 4mm
d) 4.73mm
View Answer
Answer: d
Explanation: σ=My/I or M=15000×120, y=50 and I=250000t,τ₁=15000/100t or 150/t. Τ=√(σ/2)²+τ₁² or 234.3/t =70 or t=3.35mm and leg=3.35/0.707.
6 - Question
The bracket welded to the vertical plate by means of two fillet welds. Calculate the bending stress in the welds if P=40kN, leg=4mm and e=400mm.
a) None of the listed
b) 34N/mm²
c) 24 N/mm²
d)44 N/mm²
View Answer
Answer: b
Explanation: σ=My/I where y=250mm,I=2xtx500ᵌ/12 where t=4/.707.
7 - Question
The bracket welded to the vertical plate by means of two fillet welds. Calculate size of the welds if P=40kN, leg=4mm and e=400mm. Maximum permissible value of shear stress in the weld is 70N/mm².
a) 1.4mm
b) 1.7mm
c) 2.1mm
d) 3mm
View Answer
Answer: c
Explanation: σ=My/I where y=250mm,I=2xtx500ᵌ/12 and τ₁=P/2xtx500.τ=√σ²+τ₁² or 104/t=70 and h=t/0.707.
8 - Question
While calculating bending stress in the following welded joints which of the welds moment of inertia can be neglected?
a) 1
b) None of the listed
c) Both 1 & 3
d) Both 2 & 4
View Answer
Answer: b
Explanation: Moment of inertia of 1 & 3 can be neglected about their axes but while shifting it to CG, the term Al² cannot be neglected.
9 - Question
If a circular shaft is welded to the plate by means of circumferential fillet, then the shaft is subjected to torsional moment M. If throat of weld is t, then torsional shear stress is given by
a) M/2πtr²
b) M/πtr²
c) M/4πtr²
d) None of the listed
View Answer
Answer: a
Explanation: Stress=Mr/J, here J=2πtrᵌ[I(xx)+I(yy)].
10 - Question
Magnetic crack detection method in the welds is destructible examination.
a) True
b) False
View Answer
Answer: b
Examination: Magnetic crack detector passes magnetic waves through the sample and thus flux leakage is observed.
11 - Question
Testing the ultimate strength of the weld falls in nondestructive examination.
a) True
b) False
View Answer
Answer: b
Explanation: Testing the ultimate strength leads to fracture of material and hence destructive.