Materials Flashcards
(25 cards)
What is the definition of stress in materials science?
Stress is defined as the force applied per unit area of a material.
True or False: Strain is the measure of deformation of a material.
True
What is the formula for calculating strain?
Strain is calculated as the change in length divided by the original length.
What is Young’s Modulus?
Young’s Modulus is a measure of the stiffness of a material, defined as the ratio of stress to strain.
Fill in the blank: The unit of stress in the SI system is __________.
Pascals (Pa)
What is the difference between tensile and compressive stress?
Tensile stress is the stress that occurs when a material is being pulled apart, while compressive stress occurs when a material is being compressed.
What is the yield point of a material?
The yield point is the stress at which a material begins to deform plastically.
True or False: Ductile materials can undergo significant plastic deformation before fracture.
True
What is the primary characteristic of brittle materials?
Brittle materials fracture with little to no plastic deformation.
What is the significance of the elastic limit?
The elastic limit is the maximum stress that a material can withstand without undergoing permanent deformation.
Fill in the blank: The area under the stress-strain curve represents __________.
the energy per unit volume absorbed by the material.
What does a steep slope on a stress-strain graph indicate?
A steep slope indicates a material with a high Young’s Modulus, meaning it is very stiff.
What is plastic deformation?
Plastic deformation is a permanent change in shape that occurs when a material is subjected to stress beyond its elastic limit.
True or False: The modulus of resilience is the maximum energy that can be absorbed per unit volume without permanent deformation.
True
What is the difference between elastic and plastic deformation?
Elastic deformation is reversible, while plastic deformation is permanent.
What is fatigue in materials?
Fatigue is the weakening of a material caused by repeated loading and unloading cycles.
Fill in the blank: A material that can return to its original shape after deformation is said to be __________.
elastic.
What is the definition of toughness in materials science?
Toughness is the ability of a material to absorb energy and plastically deform without fracturing.
What is the role of temperature in the properties of materials?
Temperature can affect the mechanical properties of materials, altering their strength, ductility, and toughness.
True or False: All materials exhibit the same behavior under stress.
False
What is composite material?
A composite material is made from two or more constituent materials with significantly different physical or chemical properties.
What is the significance of the strain energy density?
Strain energy density is the energy stored in a material per unit volume due to deformation.
Fill in the blank: The term __________ refers to the maximum stress a material can withstand before failure.
ultimate tensile strength.
What is the difference between hardness and toughness?
Hardness measures a material’s resistance to localized plastic deformation, while toughness measures its ability to absorb energy before fracturing.
