# Hook_s_Law - Hooks Law MECH320 Spring 08 Prepared by...

This preview shows pages 1–11. Sign up to view the full content.

1 Hook’s Law MECH320- Spring 08 Prepared by: Nasser-Eddin M., PhD

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 Table of contents ± Basic Stress-Strain Relations ± Isotropy ± Isotropic Pressure ± ± Pure Shear ± Uniaxial Stress ± Relations of Mat'l Constant ± Summary
3 Basic stress-strain relations

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4 Basic stress-strain relations
5 Basic stress-strain relations

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
6 Basic stress-strain relations In a mathematical sense, we can assume that stress and strain are related in some functional fashion as shown. Determining the appropriate function to use, however, is a formidable task, since every material will have its own behavior, and this behavior can be very complicated. As long as we restrict ourselves to modest loads, however, most materials used by engineers exhibit quite simple behavior: elastic and linear. We have already discussed the concept of elastic versus plastic behavior; we now consider linearity. In simple terms this means that stress = strain * factor. For our general stress and strain descriptions, the picture is more complicated.
7 Basic stress-strain relations

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
8 Basic stress-strain relations Since there are six stress components and six strain components, it would take 36 coefficients to relate an arbitrary stress state to the corresponding strain. Six of these constants are shown above. Fortunately, most materials do not require such a complex set of factors. In fact, we will see that more often than not we only need 2 coefficients.
9 Isotropic Material The important feature a material must have in order to allow a 2-parameter characterization is isotropy . This means it exhibits the same behavior in all directions. For example if we were to take specimens from the block …in several different orientations, and then test each sample…

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Isotopic material …we would observe the same behavior for each specimen. (For a material like wood, this would not be the case; such materials are called anisotropic .). As we are about to see, an important
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 02/07/2011 for the course MECH 320 taught by Professor D.a during the Spring '09 term at American University of Beirut.

### Page1 / 65

Hook_s_Law - Hooks Law MECH320 Spring 08 Prepared by...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online