Hardness	the quality of being solid, stiff and difficult to bend or break
Soft	changing shape easily when pressed; not stiff or hard
Wear	to become, or make something become thinner, smoother or weaker through continuous use or rubbing
Scratch hardness	The resistance of a material to being scratched
Scratch	to damage the surface of something, especially by accident, by making thin shallow marks on it
Abrasion resistance	The ability of a material to resist wear and tear from rubbing or scraping.
Abrasion	damage to a surface caused by rubbing something very hard against it
Indentation hardness	The resistance of a material to having an indentation made in it.
Indentations	Depressions made in a surface by pressure.
Fatigue	weakness in metal or wood caused by repeated bending or stretching
Metal fatigue	Fatigue that occurs in metals specifically.
Cyclic loads	Loads that are applied and removed repeatedly over time.
Flex	To bend or sway without breaking.
Micro-cracking	The formation of very small cracks in a material.
Fatigue cracking	Cracks that form in a material due to fatigue.
Fracture toughness	The ability of a material to resist fracture (breaking) under stress.
Creep	The slow or permanent deformation of a material under constant stress.
Conductivity	The ability of a material to conduct heat, electricity, or sound.
Thermal conductor	A material that conducts heat well.
Thermal insulator	A material that resists the flow of heat.
Expand	increase in size due to heating
Contract	decrease in size due to cooling
Coefficient of thermal expansion	its change in size for a given change in temperature
Coefficient of linear expansion	change in length
Be exerted on	put pressure on it
Loads	Forces applied to a structure or member
act on	To have an effect on something (apply force)
Carry or bear a load	To support a weight or force
Load-bearing	Able to support a weight or force
Loaded	Having a load applied.
Magnitude	the great size or importance of something; the degree to which something is large or important
Vector quantity or vector	a measurement with both a magnitude and a direction
Scalar quantity	A quantity that has only magnitude and no direction.
Fail	To cease to function properly or break.
Stress	physical pressure put on something that can damage it or make it lose its shape
Concentrated	Focused in a small area. (Often used with stress)
Deform	To change the shape or size of an object.
Strain	the pressure that is put on something when a physical force stretches, pushes, or pulls it
Proportional to	Having a direct relationship between two quantities.
Limit of proportionality	he point at which the stress-strain relationship becomes non-proportional.
Overstressed	Subjected to a stress that is greater than the material can safely withstand.
Disproportional	Not having a direct relationship between two quantities.
Tensile stress	Stress caused by a pulling force.
Compressive stress	Stress caused by a pushing force.
Bend	To curve or deform under pressure.
Deflect	to change direction or make something change direction, especially after hitting something
Sag	To bend downward due to weight or lack of support.
Flexure	The act of bending.
Hogs	The convex upward portion of a bent beam subjected to a load that causes bending. (The opposite of s
Shear or shearing	to break under pressure; to cut through something and make it break
Torsion or torque	A twisting force that tends to cause a material to twist along its longitudinal axis.
Twist	To turn or rotate something around its axis.
Simply supported beam	A beam that is supported at each end only.
In tension	Under the action of a pulling force.
In compression	Under the action of a pushing force.
Neutral axis	The imaginary line within a beam that experiences no stress when the beam is bent.
Structural member	An individual element that makes up a structure.
Fracture	To break or crack under stress.
Crush	To compress something violently so that it breaks or loses its shape.
Slender	Thin and long in relation to its width. (Can be more susceptible to buckling)
Buckle	To collapse suddenly due to a compressive force exceeding a critical value. (Often occurs in slender
Resist	To oppose or counteract something.
Extension	An increase in length
Elongation	The act of lengthening or stretching something
Tensile strength	The maximum stress a material can withstand while being stretched before it breaks.
Compressive strength	The maximum stress a material can withstand while being compressed before it breaks.
Elasticity	The ability of a material to deform under a stress and then return to its original shape when the st
Elastically deformed	Deformed in a way that the material will return to its original shape when the force is removed.
Stiff	difficult to bend or move
Brittle	Breaking easily with little or no plastic deformation.
Plastic	Able to undergo permanent deformation without breaking.
Plasticity	The property of a material that allows it to deform permanently under stress.
Plastically deformed	Deformed in a way that the material will not return to its original shape when the force is removed.
Malleable	Able to be hammered or pressed into a new shape without breaking.
Ductile	Able to be drawn into thin wires without breaking. (A type of plasticity)
Elastic limit	The maximum stress a material can withstand without experiencing permanent deformation
Yield point	The stress at which a material begins to deform plastically at an increased rate, even with no furth
Yields	When a material reaches the yield point and starts to deform plastically.
Fracture point	The point at which a material fractures (breaks) under stress.
Durable	likely to last for a long time without breaking or getting weaker