Elasticity-Part 1 معامل المرونه الجزء الأول

The rigid body is a useful idealized model, but the stretching, squeezing, and twisting of real bodies when forces are applied are often too important to ignore.
.
We want to study the relationship between the forces and deformations for each case.
.
If you grasp the tip of your nose between your index finger and thumb, you’ll find that the harder you pull your nose outward or push it inward, the more it stretches or compresses. Likewise, the harder you squeeze your index finger and thumb together, the more the tip of your nose compresses.
If you try to twist the tip of your nose, you’ll get a greater amount of twist if you apply stronger forces.
.
These observations illustrate a general rule. In each case you apply a stress to your nose; the amount of stress is a measure of the forces causing the defor-mation, on a “force per unit area” basis. And in each case the stress causes a deformation, or strain. More careful versions of the experiments with your nose suggest that for relatively small stresses, the resulting strain is proportional to the stress: The greater the deforming forces, the greater the resulting deformation. This proportionality is called Hooke’s law, and the ratio of stress to strain is called the elastic modulus
.
.
Faculty of Scienc El_Minya University First Grade
.
.
Personal Facebook Account :

  / vikienigmaturing  
.
Vic Academy e-mail :
[email protected]