Deformation of solids Flashcards
strong
can withstand much force with minimal extension
stiffness
resistance to deformation
toughness
can absorb much energy before breaking, much plastic deforming before breaking
ductility
ability to be drawn into wires
malleability
able to bend without cracking
hardness
resistance to scratching and pressure
brittle
material breaks with little stress
elastic
returns to original shape when load is removed
plastic
doesn’t return to original shape and has permanent deformation
yield stress
minimum stress at which material undergoes plastic deformation
compression
two coplanar forces act into object
compressive deformation
change of object shape due to compressive forces
elastic limit
force beyond which object starts deforming plastically instead of elastically
elastic potential energy
energy stored in an object when its stretched. Equal to work done to stretch object. Area of force extension graph
extension
increase of an objects length
Hooke’s Law
extension of elastic object is proportional to force applied up to limit of proportionality
limit of proportionality
point at which stress is so much that Hooke’s law no longer applies
spring constant
constant of proportionality for force and extension. More constant means more force needed
strain
ratio of objects extension to original length. Ratio of two lengths so no unit
stress
force acting per unit area. In pascals
tension
result of two forces acting on an object opposite outwardly
tensile strain
extension of object divided by original length
tensile stress
internal resistance of an object against a force that acts to deform it. Force applied per unit cross-sectional area
young modulus
ratio of stress to strain for given material. Unit in pascals
