What is the difference between strength and stiffness?

Answer 1

Strength is the amount of load or stress a materiall can take before breaking.

Toughness is an intrinsic property of the material that relates to how deep a crack or flaw can be before breaking.

Answer 2

hardness is the ability of material to resist /bear indentation or plastic deformation generally on the surface of materials.

strenght is generally withstandin stresses,fatigue etc.


toughness is the ability to absorb energy without physical change of material.

Answer 3

*Composite structures have some other unique characteristics. There is no yielding or bending point. When the ultimate strength is reached, it simply explodes or disintegrates. Metal alloys on the other hand usually exhibit a definite yield point or point at which some bending occurs before final failure. This allows us to utilize a smaller safety margin when using metals than is possible with composite structures. In other words, we must make the composite structure bigger and heavier to account for the extra safety margin. Composite materials allow engineers to create very complicated structures with reduced weight and increased strength at a lower-cost than can be achieved with some metal structures, but the limitation is usually in the manufacturing or machining methods available and not in the strength to weight ratio. In fact, it is usually possible to create a simple metal structure that is just as strong, stiff, and lightweight as is possible with most composites.