Explanation
| Material | Typical values for shear modulus (GPa) |
|---|---|
| Diamond | 478. |
| Steel | 79.3 |
| Copper | 44.7 |
| Titanium | 41.4 |
| Glass | 26.2 |
| Aluminium | 25.5 |
| Polyethylene | 0.117 |
| Rubber | 0.0006 |
| Glycerin | 0.000000255 |
| Water | 0.00000000016 |
The shear modulus is one of several quantities for measuring the stiffness of materials. All of them arise in the generalized Hooke's law:
- Young's modulus describes the material's response to linear strain (like pulling on the ends of a wire or putting a weight on top of a column),
- the bulk modulus describes the material's response to uniform pressure (like the pressure at the bottom of the ocean or a deep swimming pool)
- the shear modulus describes the material's response to shearing strains (like cutting it with dull scissors).
The shear modulus is concerned with the deformation of a solid when it experiences a force parallel to one of its surfaces while its opposite face experiences an opposing force (such as friction). In the case of an object that's shaped like a rectangular prism, it will deform into a parallelepiped. Anisotropic materials such as wood, paper and also essentially all single crystals exhibit differing material response to stress or strain when tested in different directions. In this case one may need to use the full tensor-expression of the elastic constants, rather than a single scalar value.
Read more about this topic: Shear Modulus
Famous quotes containing the word explanation:
“To develop an empiricist account of science is to depict it as involving a search for truth only about the empirical world, about what is actual and observable.... It must involve throughout a resolute rejection of the demand for an explanation of the regularities in the observable course of nature, by means of truths concerning a reality beyond what is actual and observable, as a demand which plays no role in the scientific enterprise.”
—Bas Van Fraassen (b. 1941)
“There is no explanation for evil. It must be looked upon as a necessary part of the order of the universe. To ignore it is childish, to bewail it senseless.”
—W. Somerset Maugham (1874–1965)
“Are cans constitutionally iffy? Whenever, that is, we say that we can do something, or could do something, or could have done something, is there an if in the offing—suppressed, it may be, but due nevertheless to appear when we set out our sentence in full or when we give an explanation of its meaning?”
—J.L. (John Langshaw)