Sample Exam 2 
Machine Elements Design 
SE2 
Student Name: 
Student No. 
1) Define the following: 

a Coil spring mean diameter D:
b Spring buckling:
d Stress of solid torsion bar under torque T:
1) B Write the types of coil spring wire stresses:

Stress type 
1 

2 

3 

1) C If k_{1 }= 1000 N/mm, k_{2} =
500 N/mm
i Show; which one of the spring configurations will have a greater spring rate?


iii What is the deflection of the spring number 1 if the spring load is 1000 N
2 A coil spring has the following data:  mean coil diameter D = 150 mm  wire diameter d = 15 mm  number of total coils is 10  ends of the spring are squared and ground  the shear modulus of the spring material G = 81400 MPa  the free length of the spring L_{f} = 360 mm 

Find:
a) the spring index C
b) the Wahl factor K_{w}
c) the maximum stress on the spring due to load P = 4000 N
d) the solid length L_{s}
e) the deflection δ under the load P
f) the maximum deflection δ_{max} of the spring
g) the spring inside coil diameter D_{i}
h) check the stress of the spring using the nomogram using: D, d, P, C
3 a) Find the reactions at point A and B from the figure shown.

b) If the spring is replaced by a leaf spring where 2F = 4000 N, 2L = 1000 mm, number of leaves (n) = 4, leaf width (b’) = 50 mm, leaf height (h)= 9 mm. Find the stress on the spring (σ_{b}). 

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