MCQs on Eccentrically Loaded Riveted Joints
1 - Question
This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Eccentrically Loaded Riveted Joints”.
Figure 1
Answer the following questions in context to figure 1. A bracket is attached to a vertical wall by means of four rivets. Find the rivet which is under maximum stress.
a) 1 and 4
b) 2 and 3
c) 3 and 1
d) 4 and 2
View Answer
Answer: a
Explanation: Primary Shear act vertically upward on all the rivets. Secondary shear is proportional to the distance from CG. Hence rivets 1 and 4 are under maximum stress.
2 - Question
Calculate the primary shear stress on each rivet if P=30kN and diameter of rivets is 15mm.
a) None of the listed
b) 21.2 N/mm²
c) 42.4N/mm²
d) 169.6 N/mm²
View Answer
Answer: c
Explanation: τ₁=P/4A or 7500/A.
3 - Question
If secondary shear stress acting on any bolts is given by Cxr₁ where r₁ is the distance of bolt from CG, then find the value of C. Bolts are equidistant with spacing of 100mm. Force P=30kN.
a) 46 b) 50 c) 72 d) 64
View Answer
View Answer
Answer: c
Explanation: C=Pe/[r₁²+r₂²+r₃²+r₄²].
4 - Question
Calculate the effective force in vector form to which rivet 2 is subjected. Bolts are separated by 100mm and force P=30kN.
a) 7500j+3600i
b) 7500j-3600i
c) -7500j-3600i
d) None of the listed
View Answer
Answer: b
Explanation: Primary force=7500j, Sec Force=Cx50(-i) where C=72.
5 - Question
Calculate the effective force in vector form to which rivet 4 is subjected. Bolts are separated by 100mm and force P=30kN.
a) 7500j+7200i
b) None of the listed
c) 7500j+7200i
d) 7500j+7200i
View Answer
Answer: d
Explanation: Primary force=7500j, Sec Force=Cx100 i where C=72.
6 - Question
Calculate the diameter of the rivets if permissible shear stress is 60N/mm². Bolts are separated by 100mm and force P=30kN.
a) 10mm
b) 12mm
c) 13mm
d) 15mm
View Answer
Answer: d
Explanation: Magnitude of force acting on Bolt 4 or Bolt 1=√7500²+7200² or 10396.6=πd²τ/4.
7 - Question
Are the bolts 2 and 3 under same force?
a) Yes
b) No
c) Depends on nature of force whether it is of shear or bending in nature
d) Can’t be determined
View Answer
Answer: b
Explanation: Primary shear force is same but secondary shear forces direction are different in the two bolts.
8 - Question
Are the bolts 2 and 3 subjected to same magnitude of force?
a) True
b) False
View Answer
Answer: a
Explanation: Although the vectors are different for the forces on two bolts but their magnitudes are same.
9 - Question
Can we use the rivets of diameter 18mm in the following case if P=30kN and bolts are separated by 100mm each. Maximum permissible shear stress is 60N/mm².
a) Always
b) Never
c) In some cases
d) Cannot be determined
View Answer
Answer: a
Explanation: The minimum diameter required for the rivets is obtained 15mm. Any rivet greater than this diameter is safe to use.