2006-07-04 05:30:28 · 6 answers · asked by mjsmito 1 in Science & Mathematics ➔ Engineering
Strength is a measure of the force needed to break the intermolecular bonds in a materials.
It is usally measured as a stress or pressure (force/Area), and the yeild strength of a material (which is used in Engineering applications) is the allowable pressure that the material is subjected to before it will exhibit permanent deformations
Stiffness is a measure of how much a material will deflect in a plastic matter. There are many different types of stiffness, axial stiffness, bending stiffness, torsional stiffness etc.
Stiffness is measured in a Force/Length and is specified as the amount of force required for the material to deflect 1 unit of length
2006-07-04 07:32:31 · answer #1 · answered by Aaron G 2 · 0⤊ 0⤋
Based on the question, I believe you are referring to a beam, such as a 2"X6" piece of wood. In this case the stiffness is greatly influenced by its depth in the direction of the load. For instance, if the 2"X6" (2" up & down) is supported at each ends by a saw horse, and a person sits in the middle. The board will sag a certain amount. If the board is rotated such that the 6" dimension is up & down, and the same person sits in the middle, the board will not sag nearly so much. The stiffness of the board is relative to its depth, i.e. deeper beams have greater stiffness. In this same way, the strength of the board is proportional to its stiffness. A 2"X6" board loaded in the plane of the 6" depth has more strength than the same board rotated so its load is resisted by the 2" dimension. The strength is determined how much force is resisted by the section of the beam.
2006-07-04 13:14:27 · answer #2 · answered by bonacker 4 · 0⤊ 0⤋
Stiffness refers to how well something bends, something that on a scale of 1-10 10 being the stiffest, has a stiffness of 10, could have no strength and just snap, however strength defines how much pressure it can withstand before giving.
So something with low stiffness and low strength can, in certain situations, hold as much as something with high stiffness and high strength.
2006-07-04 05:34:44 · answer #3 · answered by Archangel 4 · 0⤊ 0⤋
Stiffness is measured in terms of deflections under load of a given structure. Strength in terms of allowable or ultimate (before failure) stresses in the material.
2006-07-04 05:45:38 · answer #4 · answered by Robert A 5 · 0⤊ 0⤋
Stiffness is a materials flexibility, the amount of effort it takes to change its shape once formed. Strength is a materials ability to not crack, break, or suffer some other form of catastrophic failure under stress (pressure, extreme temperatures, etc).
2006-07-04 05:35:12 · answer #5 · answered by psilohead 2 · 0⤊ 0⤋
stiffness is a noticible resilience to bending or motion and an increase in brittleness ,strength is the proportional ability to perform a task or with- stand opposing forces and retain its shape and or purpose
2006-07-04 06:18:42 · answer #6 · answered by Book of Changes 3 · 0⤊ 0⤋