55 Questions
What is the region in the stress-strain curve where Hooke's law is obeyed?
Region O to A
What is the point in the stress-strain curve known as the yield point?
Point B
What property of the material does the stress-strain curve help us understand?
How a given material deforms with increasing loads
What is the stress-strain curve a graphical representation of?
Relation between stress and strain
What does the applied force per unit area represent in the stress-strain curve?
Stress
What is the term used to describe the portion of the stress-strain curve where strain increases rapidly even for a small change in stress?
Plastic deformation
At which point on the stress-strain curve does the material exhibit permanent set and strain is not zero even when the stress is zero?
Point C
What is the term used to describe the point on the stress-strain curve that represents the ultimate tensile strength of the material?
Ultimate tensile strength
When does additional strain occur even by a reduced applied force and fracture ultimately occurs?
At point E
If the ultimate strength and fracture points on the stress-strain curve are close, what is the material said to be?
Brittle
Stress and strain are directly proportional in the region from A to B on the stress-strain curve
False
The yield point on the stress-strain curve is also known as the elastic limit
True
The stress-strain curve for compression and shear stress is different from that of tension
True
The stress-strain curve helps us understand how a material deforms under varying loads
True
The stress-strain curve for a given material is always linear from O to A
False
True or false: When the load is removed at point C between B and D, the body regains its original dimension.
False
True or false: Beyond the ultimate tensile strength point, additional strain is produced even by a reduced applied force.
True
True or false: If the ultimate strength and fracture points D and E are close, the material is said to be ductile.
False
True or false: The material is said to have a permanent set when the stress is zero but the strain is not zero.
True
True or false: The deformation is said to be plastic deformation when the ultimate tensile strength and fracture points D and E are far apart.
False
From the graph, we can see that in the region between O to A, the curve is ______.
linear
The point B in the curve is known as ______ and the corresponding stress is known as yield strength (σ y ) of the material.
yield point
In the region from A to B, stress and strain are not ______.
proportional
The stress-strain curves vary from material to ______.
material
The body regains its original dimensions when the applied force is ______.
removed
Beyond the ultimate tensile strength point, additional strain is produced even by a reduced applied force and fracture occurs at point ______
E
The portion of the curve between B and D shows ______
plastic deformation
If the ultimate strength and fracture points D and E are close, the material is said to be ______
brittle
When the load is removed, say at some point C between B and D, the body does not regain its original ______
dimension
If they are far apart, the material is said to be ______
ductile
Match the following terms with their descriptions:
Elastic limit = The point on the stress-strain curve beyond which permanent deformation occurs Plastic deformation = Deformation that occurs beyond the yield strength and does not recover upon removal of the load Ultimate tensile strength = The maximum stress a material can withstand before fracturing Brittle material = A material in which the ultimate strength and fracture points are close
Match the following points on the stress-strain curve with their descriptions:
Point C = The point where the load is removed between B and D, causing the material to exhibit permanent set Point D = Represents the ultimate tensile strength of the material Point E = The point where fracture occurs, usually beyond the ultimate tensile strength Point B = The yield point, where the material transitions from elastic to plastic deformation
Match the following statements with the correct material behavior:
Ductile material = Material in which the ultimate strength and fracture points D and E are far apart Brittle material = Material in which the ultimate strength and fracture points D and E are close Elastic deformation = Material behavior in the region from O to A on the stress-strain curve Plastic deformation = Material behavior in the region beyond the yield point
Match the following terms with their definitions:
Permanent set = Deformation that remains in a material even when the stress is zero Stress = Force per unit area applied to a material Strain = Measure of deformation in a material relative to its original dimension Fracture = The point at which a material breaks due to applied stress
Match the following material behaviors with their descriptions:
Elastic deformation = Material behavior in which the material returns to its original shape after the load is removed Plastic deformation = Material behavior in which the material does not return to its original shape after the load is removed Ductile material = Material that can undergo significant plastic deformation before fracturing Brittle material = Material that fractures with little or no plastic deformation
Explain the concept of plastic deformation as it relates to the stress-strain curve.
Plastic deformation occurs when the stress developed exceeds the yield strength and strain increases rapidly, even for a small change in stress. This leads to a permanent set in the material.
What is the significance of the ultimate tensile strength (σu) point on the stress-strain curve?
The point σu represents the maximum stress a material can withstand before additional strain is produced even by a reduced applied force, ultimately leading to fracture.
Differentiate between brittle and ductile materials based on the stress-strain curve.
If the ultimate strength and fracture points are close, the material is brittle. If they are far apart, the material is ductile.
Describe the behavior of a material when it exhibits permanent set.
When a material exhibits permanent set, even when the stress is zero, the strain is not zero, indicating that the material has undergone plastic deformation and does not return to its original dimensions.
Explain the relationship between stress and strain in the portion of the curve between points B and D on the stress-strain curve.
In the portion between B and D, the stress developed exceeds the yield strength, leading to rapid strain increase and plastic deformation in the material.
What type of material can be stretched to cause large strains and returns to its original shape?
Elastomer
What behavior is exhibited by the elastic tissue of aorta in the stress-strain curve?
It does not obey Hooke’s law over most of the region
What is the term used for substances like rubber and tissue of aorta which can be stretched to cause large strains?
Elastomers
Rubber can be stretched to several times its original length and still returns to its original shape:
True
The stress-strain curve for the elastic tissue of aorta obeys Hooke’s law over most of the region:
False
Elastomers are substances like tissue of aorta and rubber which can be stretched to cause large strains:
True
Rubber can be pulled to several times its original length and still returns to its original shape
elastomers
Although elastic region is very large, the material does not obey Hooke’s law over most of the region
elastic tissue of aorta
There is no well defined plastic region for substances like tissue of aorta, rubber etc. which can be stretched to cause large strains
elastomers
Explain the behavior of elastomers as described in the text.
Elastomers are substances like tissue of aorta and rubber which can be stretched to cause large strains and still return to their original shape.
What is the significance of the ultimate tensile strength (σu) point on the stress-strain curve?
The ultimate tensile strength point represents the maximum stress a material can withstand before it fractures, providing insight into the material's strength.
What is the behavior exhibited by the elastic tissue of aorta in the stress-strain curve?
The elastic tissue of aorta exhibits a large elastic region, but it does not obey Hooke’s law over most of the region and has no well-defined plastic region.
Rubber can be pulled to several times its original length and still returns to its original shape
elastomers
Although elastic region is very large, the material does not obey Hooke’s law over most of the region
elastic tissue of aorta
Substances like tissue of aorta, rubber etc. which can be stretched to cause large strains are called
elastomers
Study Notes
Stress-Strain Curve
- The stress-strain curve for a material under tensile stress can be obtained experimentally by stretching a test cylinder or wire and recording the fractional change in length (strain) and the applied force needed to cause the strain.
- A graph is plotted between the stress (applied force per unit area) and the strain produced, with the resulting curve varying from material to material.
- The stress-strain curve helps us understand how a given material deforms with increasing loads.
Elastic Region
- The region between O to A on the stress-strain curve is linear, where Hooke's law is obeyed.
- In this region, the body regains its original dimensions when the applied force is removed.
- The solid behaves as an elastic body in this region.
Yield Point and Yield Strength
- The point B on the stress-strain curve is known as the yield point (also known as elastic limit).
- The corresponding stress at the yield point is known as the yield strength (σ y) of the material.
- In the region from A to B, stress and strain are not proportional, but the body still returns to its original dimension when the load is removed.
Test your knowledge of stress-strain curves with this quiz. Explore the relationship between stress and strain in materials under tensile stress and gain a better understanding of the properties of materials under different forces.
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