Deformation of solids Flashcards
what is a Tensile force?
a force that stretches a body causing deformation
define deformation
changing the size or shape of an object
What is a compressive force?
When two forces compress a body causing deformation
what is tensile strength
the amount of load or stress a material can handle before it stretches and breaks (measured in Paskals (Pa))
State Hookes law
the extension of a material is directly proportional to the applied force as long as its elastic limit is not exceeded
state Hooke’s law as an equation
x proportional F
therefore F = Kx
where:
F = force
x = elastic limit
K = konstant
what is natural length
the length of an object when no force is applied
what is elastic limit?
the length at which an object stretched passed it will deform and not return to its natural length
what is a springy constant
the force required per unit extension (the greater the springy constant the stiffer the spring)
what is the formula for finding the springy content in springs in series
1/Ktotal = 1/k1 + 1/k2 ….
what is the formula to find the springy constant in springs in parelell
Ktotal = k1 +k2 + …
what is stress?
the force applied per unit cross sectional aria
sigma = force / aria
what is strain?
the extention per unit length
epsalon = extention/lenth
what is young modulus
a mesure of the ability of a material to withstand changes in legth with added load (ie how stiff a material is)
how do you calculate the young modulus?
E = Stress/strain
what is an elastic deformation?
when the load is removed it will return to its original shape
what is a plastic deformation?
when the load is removed it will NOT return to its origonal shape
how do brittle materials deform?
they have very little to no plastic reagon (ie they strech)
how do ductile matterials deform?
materials have a larger pastic reagon
define elastic potential energy
the energy stored within a material when it is stretched or compressed
