Mechanical Properties of Materials Flashcards
Define Tensile Stress
Force per unit cross sectional area (Pascals)
Define Tensile strain
Extension per unit length
What is Youngs Modulus
A constant that doesn’t change for a given material, it represents the stiffness property of that material (pascals)
What is the gradient of a stress strain graph equal to
Youngs Modulus
What is the area under the elastic part of a stress strain graph equal to
Energy Stored
What is the area under both the plastic and elastic parts of a stress strain curve equal to
Toughness
What does Hookes Law State
Force is directly proportional to extension up the limit of proportionality
What is the elastic limit
The point at which beyond additional force will lead to plastic deformation and it will no longer return to its original shape
What is Poissons Ratio
The ratio of lateral and axial strain- materials under tension tend to decrease in width whilst those under compression get wider. Poissons ratio is the relative contraction normal to the applied load to the relative extension in the direction of the applied load
define Strength
The amount of stress a material can withstand before yielding or fracturing
Define elasticity
This is the ability of a material to return to its original dimensions after underloading
Define plasticity
On unloading materials do not regain their original dimensions and their deformation is permanent
Define ductility
The ability of materials to withstand appreciable deformation before failure
Define Brittle
Shows little or no elastic deformation, failure occurs because planes of atoms split apart
Define Creep
The time dependent strain occurring when solids are subjected to a constant applied stress
