Materials Flashcards
What is plastic behaviour?
A material acts plastic ally if after being stretched, it doesn’t return to its original shape.
How do you calculate stress?
Force/area (pa)
How do you calculate strain?
Extension/original length (no units)
What is hookes law?
The extension of an object is proportional to the force that causes it, providing the elastic limit is not reached. F=kx
What is hysteresis?
When energy stored during loading a material and the energy released during unloading is different.
What is a BRITTLE material?
A material that breaks with little or no plastic deformation.
What is a DUCTILE material?
One that can be drawn into wires and show plastic deformation under tensile stress before breaking.
What is a HARD material?
Materials that resist plastic deformation by surface indentation or scratching.
What is a POLYMERIC material?
A material made of many smaller molecules bonded together (monomers), often making tangled long chains.
What is a STIFF material?
A material which can resist a tensile force.
What is elastic behaviour?
A material acts elastically if after being stretched it returns to original shape.
What is the area under a stress strain graph equal to?
Work done/volume
