Exam. 1-C

Machine Elements Design

E1c

Student Name:

Student No.

 

1- Show the following using stress-strain curve A:

 A- Fracture point

 B- Material yield point
C- If the two curves represent steel and cupper, which is which?, and why?

 

 

B) Define the following:

a- Material ultimate strength:

 

b- Stress:

c- Second moment of area (I) :

 

2- A) Find the () of the following area (all dimensions in cm):
The circle diameter is 10 cm, and the square side length is 2 cm.

 

 

 

 

 

B- Find (Ix) of the following shape (all dimensions in cm):

All the thicknesses is 2 cm.

 

 

 

 

3- A steel bar of an area of 20 mm2 is subjected to a tensile load of 1000 N at the top, and 1000 N, at the middle.

A)  Chose suitable steel if the required SF is 3.

 

 

 

 

 

 

 

B) Find the strain due to the tensile forces, if the modulus of elasticity of the shaft material E= 20x104 MPa.

 

 

 

 

 

 

 

 

 

4- Find the bending stress (σb) on the shaft at (A) and (B):

The solid shaft diameter is 30 mm.