Sohag university Faculty of engineering
First year Civil Eng. Dept.
Strength & properties of materials 1
Tension Behavior and mechanical properties of reinforced steel bars
Question 1:-
A tension test was carried out on a steel specimen of 15mm diameter and 150mm length. The results were as follow:
10
12
13
12.5
11.5
8.5
7.5
7.6
3.8
P (ton)
36
32
25
19
13
4.2
1.6
.12
.o6
▲L (mm)
What is the type of this specimen?
Draw ordinary stress-strain diagram.
Obtain the following: proportional stress-yield stress-ultimate stress-fracture stress-elastic modulus-resilience-toughness.
Determine the secant and tangent modulus at load 9.5t.
What will be the elongation for a short specimen of 20mm diameter from the same material at load 6t?
Question 2:-
The results of a tension test for long steel specimen of 12mm diameter were as follow:
P(ton)
2.5
5
5
5.3
6.2
7
7.2
6.8
▲L(mm)
.6
1.2
1.4
2.8
9.2
19
40
48
Draw ordinary stress – strain diagram and determine:
Tensile strength – yield stress – stiffness – modulus of toughness – ductility – elongation corresponding to load 6.5t.
Question 3:-
Tension test was carried out on standard long specimen of 1.6cm diameter. the results were as follow:
P(ton)
1
2.8
5.2
6.3
7.8
8.8
9.4
9.85
10.4
11.2
10
▲L(mm)
.016
.05
.105
.125
.144
.195
.58
1.42
3.94
5.8
7.9
Plot stress – strain diagram.
Calculate: toughness and modulus of toughness – initial modulus of stiffness – secant modulus at load 9t – proof stress – proportional load – tangent modulus at load 8t.
Question 4:-
A tension test was carried out on a standard specimens of 25mm diameter.
Length
80
160
240
320
400
480
elongation
38
28
25
23
22
21
Draw the previous data with suitable scale and find the constants of elongation equation.
Use these constants to predict the elongation of a standard long specimen from the same type having length of 200mm.