Strain energy is the energy stored in a material when it is deformed elastically. This energy is released when the material returns to its original shape after the applied load is removed.
What is anisotropy in materials?
A Different properties in different directions
B Identical properties in all directions
C Ability to absorb energy
D Ability to return to original shape
Anisotropy refers to the property of a material where its mechanical or physical properties vary depending on the direction in which they are measured, such as in composite materials.
What is viscoelasticity?
A Elastic behavior of materials
B Behavior combining viscous and elastic properties
C Stress recovery after loading
D Permanent deformation under stress
Viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. These materials have time-dependent strain and recover after stress is removed, but with some delay.
What is the typical behavior of composite materials?
A Uniform strength in all directions
B Inelastic under stress
C No deformation before failure
D Properties are tailored by combining materials
Composite materials are engineered by combining two or more materials to achieve desired properties, such as high strength, low weight, and increased toughness. The combination of materials allows for tailored properties.
What is the primary factor that influences a material’s toughness?
A Hardness
B Ductility and strength
C Elasticity
D Poisson’s ratio
Toughness is a material’s ability to absorb energy and plastically deform without fracturing. It is influenced by both the material’s ductility (ability to deform) and strength (ability to resist fracture).
What does the load-displacement curve represent?
A Force versus time
B Stress versus strain
C Load versus displacement in a material
D Energy versus deformation
The load-displacement curve represents the relationship between the applied load and the displacement of a material or structure. It is essential for understanding the material’s response to external forces.
What is the term for the point where a material’s stress-strain curve ends in elastic deformation?
A Elastic limit
B Yield point
C Fracture point
D Ultimate point
The elastic limit is the maximum stress a material can endure while still returning to its original shape once the load is removed. Beyond this limit, the material will undergo permanent deformation.
What is the main characteristic of a material’s toughness?
A Resistance to indentation
B Resistance to fracture
C Ability to return to original shape
D Ability to absorb energy without fracturing
Toughness is the ability of a material to absorb energy through deformation before failure. It is critical in applications requiring materials to withstand impact or shock loads without breaking.
What is a typical property of a viscoelastic material?
A Instantaneous deformation
B Time-dependent deformation
C No deformation under stress
D No recovery after stress removal
Viscoelastic materials exhibit time-dependent deformation. When stress is applied, they deform initially like viscous materials but gradually recover, behaving elastically over time, such as in polymers.
What is the significance of strain energy?
A Energy that can be recovered after deformation
B Energy consumed during deformation
C Energy lost due to internal friction
D Energy used to break the material
Strain energy represents the energy stored in a material when it is deformed elastically. This energy is recoverable when the material returns to its original state after the applied force is removed.
Which of the following materials typically show anisotropic behavior?
A Metals
B Rubber
C Wood
D Glass
Wood is an anisotropic material, as its properties, such as strength and stiffness, vary depending on the grain direction. This makes wood stronger along the grain and weaker across it.
What does the term “plastic deformation” refer to?
A Elastic recovery after stress
B Reversible stretching
C Deformation at high temperatures
D Permanent change in shape under stress
Plastic deformation occurs when a material undergoes a permanent change in shape due to stress. This happens when the stress exceeds the material’s yield strength, and the deformation does not reverse when the load is removed.
What happens to a material in the plastic region of the stress-strain curve?
A It returns to its original shape
B It deforms permanently
C It fractures instantly
D It undergoes no further deformation
In the plastic region of the stress-strain curve, the material undergoes permanent deformation. Beyond the yield point, the material does not return to its original shape when the stress is removed.
What is the key feature of composite materials?
A Tailored properties
B High resistance to corrosion
C Inflexibility
D Low cost
Composite materials are engineered by combining different materials to produce a product with specific, desired properties, such as increased strength, reduced weight, and improved durability.
How is toughness generally measured in materials?
A By its hardness
B By its ability to withstand impact
C By the strain at failure
D By the modulus of elasticity
Toughness is measured by a material’s ability to absorb energy before breaking. Impact tests like Charpy and Izod are commonly used to measure the toughness of materials.