This presentation discusses fiber strength and strain. It defines stress as the resistance per unit area to deformation when an external force acts on a body. Strain is defined as the deformation per unit length. A stress-strain curve is presented for textile fibers, showing the relationship between stress and strain. Hooke's law is described, which states that within the elastic limit, the ratio of stress to strain is constant. This constant is known as the modulus of elasticity or Young's modulus. The presentation concludes with a discussion of the strength versus toughness dilemma by examining the stress-strain curve.
2. Presented by-
Nadia Afrin
ID 181-001-4111
Arafat Ahmed Apu
ID 181-007-4111
Md. Asraful Kabir Monna
ID 181-022-4111
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MBA-181(AM) BATCH
3. TOPICS
The Topic Is about Fiber
Strength (Stress) & Strain
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4. CONTENTS
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1. Definition of Strength (Stress)
2. Definition of Strain
3. Stress-Stain Curve for Textile Fibre
4. Stress-Stain & Modulus Curve
5. Relation between Stress and Strain
6. Discussion on Strength vs. toughness
dilemma (Curve)
7. References
5. Strength (Stress):
When some external force acts on a body. It undergoes
some deformation. As the body undergoes deformation,it
sets up some resistance to deformation. This resistance per
unit area to deformation is known as stress.
Mathematically-
Stress, (S) = F/A
Where,
S=stress
F=force acting on the body
A=cross sectional area
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6. Strain:
Strain is the term use to relate the elongation with the
initial length. The deformation per unit length is known
as strain.
Mathematically-
Strain, (€) = l/ L
Where,
€=strain
l=change of length
L=original length
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8. Stress, = F/A
Strain, = l/ L
Modulus, E = Stress/Initial strain
Modulus high = Material is stiff
Modulus low = Material is tough
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9. Relation between Stress and Strain
Hooke’s Law:
“Within Elastic limit the ratio of stress applied to
strain developed is constant”.
The constant is known as Modulus of elasticity or
Young’s Modulus or Elastic Modulus.
Mathematically:
E= Stress/Strain
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11. References:
Class Lecture: Delivered by Dr. Md. Hasan Ikbal
Books: Physical Properties of Textile Fibres (4th Edition).
By- W.E. Mortan and J.W.S. Hearle.
Internet: wikipedia.com google.com
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1155612/
http://nptel.ac.in/courses/116102029/40
http://physicsnet.co.uk/a-level-physics-as-a2/materials/young-modulus/
http://www.softschools.com/formulas/physics/youngs_modulus_formula/507/
https://www.s-cool.co.uk/a-level/physics/stress-and-strain/revise-it/definitions-of-stress-
strain-and-youngs-modulus
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