Here We are showing Typical Stress Strain Diagram ( with example ) and point outing important parameters. Course Name: Elements of Machine Dynamics and Design Course Code: TE334 Submitted To: Arnab Mustafi Arka Lecturer DEPARTMENT OF TEXTILE ENGINEERING Daffodil International University

1. DaffodilInternationalUniversity
(DIU)

2. SubmittedTo:
Arnab Mustafi Arka
Lecturer
DEPARTMENT OF TEXTILE ENGINEERING
DaffodilInternationalUniversity
Course Name: Elements of Machine Dynamics and Design
Course Code: TE334
01 Date: 12.04.21

3. Draw Typical Stress Strain Diagram ( with example
) and point out important parameters
Presentation Topic:
02 Date: 12.04.21

4. Name: Rokea Akter Rupu
ID: 181-23-5243
Sec: C
03 Date: 12.04.21

5. What is Stress & Strain?
Stress:
Stress is the force applied to a material, divided by the material's cross-sectional area. Strain is
the deformation or displacement of material that results from an applied stress.
● Tensile Stress: It is the force applied per unit area which results in the increase in length (or area) of
a body. Objects under tensile stress become thinner and longer.
● Compressive Stress: It is the force applied per unit area which results in the decrease in length (or
area) of a body. The object under compressive stress becomes thicker and shorter.
Strain:
According to the strain definition, it is defined as the amount of deformation experienced by the body in
the direction of force applied, divided by initial dimensions of the body.
● Tensile Strain: It is the change in length (or area) of a body due to the application of tensile stress.
● Compressive Strain: It is the change in length (or area) of a body due to the application of
compressive strain
04 Date: 12.04.21

6. Stress & Strain:
Stress:
In mechanics, stress is defined as a force applied per unit area. It is given by the formula
σ=FA
where,
σ is the stress applied
F is the force applied
A is the area of force application
The unit of stress is N/m2
Strain:
The relation for deformation in terms of length of a solid is given below.
ϵ=δlL
where,
ϵ is the strain due to stress applied
δl is the change in length
L is the original length of the material.
The strain is a dimensionless quantity as it just defines the relative change in shape.
05 Date: 12.04.21

7. Name: Md. Raisul Islam Rifat
ID: 181-23-5236
Sec: C
06 Date: 12.04.21

8. Stress-Strain Curve
The stress-strain graph has different
points or regions as follows:
1. Proportional limit
2. Elastic limit
3. Yield point
4. Ultimate stress point
5. Fracture or breaking point
07 Date: 12.04.21

9. Proportional Limit:(Hooke's Law)
From the origin O to the point called proportional limit, the stress-strain
curve is a straight line. This linear relation between elongation and the
axial force causing was first noticed by Sir Robert Hooke in 1678 and is
called Hooke's Law that within the proportional limit, the stress is directly
proportional to strain or
σ∝εσ∝ε or σ=kεσ=kε
The constant of proportionality k is called the Modulus of Elasticity E
or Young's Modulus and is equal to the slope of the stress-strain diagram
from O to P. Then
σ=Eε
08 Date: 12.04.21

10. Name: Sharan Das Saj
ID: 181-23-5245
Sec: C
09 Date: 12.04.21

11. Elastic Limit
10 Date: 12.04.21

12. Yield Point
The yield point is defined as the point at
which the material starts to deform
plastically. After the yield point is passed,
permanent plastic deformation occurs. There
are two yield points
(i) upper yield point
(ii) lower yield point
a point where there is a sharp increase in the
object's strain that does not correlate with an
increase in stress. The yield point happens
after an object has reached its yield stress.
11 Date: 12.04.21

13. Name: Shakil Ahmed
ID: 181-23-5234
Sec: C
12 Date: 12.04.21

14. Ultimate stress point
Maximum Strength Before Breaking.
On the graph point U is the ultimate
stress point. After point U material have
very minute or zero strength to face
further stress.
13 Date: 12.04.21

15. Fracture or breaking point
Material Physically Separates.
Even though the corresponding
stress may be less than the
ultimate strength at this point.
14 Date: 12.04.21

16. Name: Rajath Roy
ID: 181-23-5238
Sec: C
15 Date: 12.04.21

17. Example
Figure: Stress–strain curves of rotor spun yarn at different strain rates
16 Date: 12.04.21

18. Allowable Stress, Working Stress, and
Factor of Safety
Allowable Stress : The allowable stress
or allowable strength is the maximum
stress (tensile, compressive or bending)
that is allowed to be applied on a
structural material.
The allowable stresses are generally
defined by building codes, and for steel,
and aluminium is a fraction of their yield
stress (strength)
17 Date: 12.04.21

19. Reference:
1. https://byjus.com/physics/stress-and-strain/
2. https://mathalino.com/reviewer/mechanics-and-strength-of-materials/stress-strain-diagram
3. https://www.setareh.arch.vt.edu/safas/007_fdmtl_30_allowable_stress.html#:~:text=The%20allowa
ble%20stress%20or%20allowable,their%20yield%20stress%20(strength)%3A
4. https://www.thestudentroom.co.uk/showthread.php?t=4603690
5. https://openstax.org/books/university-physics-volume-1/pages/12-3-stress-strain-and-elastic-
modulus
6. https://mechaengineeringonline.blogspot.com/2016/05/working-stress-and-factor-of-safety.html
7. Stress-strain curves of rotor spun yarn at different strain rates. | Download Scientific Diagram
(researchgate.net)
8. https://www.chegg.com/learn/physics/introduction-to-physics/breaking-point
9. https://www.engineeringintro.com/mechanics-of-structures/stress-strain-
curveexplanation/#:~:text=Ultimate%20stress%20point%20is%20the,on%20the%20stress%20strain
%20graph
18 Date: 12.04.21

20. 19 Date: 12.04.21