Machine Elements Design	Exam 1
Student Name:	St. No.

1- What are the differences and/or the relations between the following:

A- Stress (s), Strain (ε):

B- Moment (M), Torque (T):

C- Normal stress (σ), Shear stress (τ):

D- Second moment of area (I), Polar moment of area (J):

2- A structure suspended by EN3 tie-bars is equivalent to a load of F = 120,000 N. The tie-bars each have a diameter of d = 24 mm. If the SF is 9, calculate the minimum number of tie-bars (n).

3- Find the stress at point A due to the Forces shown in the figure.

Where: F_x = 100 N, F_y = 150 N, F_z = 200 N, L= 40 mm, H= 20 mm, d= 4 mm

A = ………………………..………

I = …………………………………

J = …………………………………..

F	AT “A”	Normal force	Shear Force	Moment	Torque
Fx	Load
	Stress
Fy	Load
	Stress
Fz	Load	X	Fz = 200 N	M = Fz  L      = 200 x 40      = 8000 N mm	X
	Stress	X	τz = Fz/A = 200/ =	σb = M y /I = - 8000 x 2/ =	X