Elastic limit

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The elastic limit is the maximum stress a material can undergo at which all strains are recoverable. (i.e., the material will return to its original size after removal of the load). At stress levels below the elastic limit the material is said to be elastic.

Once the material exceeds this limit, it is said to have undergone plastic deformation (also known as permanent deformation). When the stress is removed, some permanent strain will remain, and the material will be a different size.

The concept of elastic limit should not be confused with the proportional limit, which is the stress above which the relationship between stress and strain are no longer linearly proportional. Ordinarily, the elastic limit is greater than the proportional limit; however, for many materials (such as steel), the two are close enough to be identical for all practical purposes.

For elastomers, such as rubber, the elastic limit is extremely large. The material will not undergo any plastic/permanent deformation. Initially it can be easily stetched but becomes stiffer as the stress increases. Once it is released, it will return to its original length.

203.110.246.230 02:54, 30 March 2007 (UTC)ɬ==References==

Engineer's Handbook
Boresi, A. P., Schmidt, R. J., and Sidebottom, O. M. (1993). Advanced Mechanics of Materials, 5th edition. John Wiley & Sons. ISBN 0-471-55157-0
Oberg, E., Jones, F. D., and Horton, H. L. (1984). Machinery's Handbook, 22nd edition. Industrial Press. ISBN 0-8311-1155-0
Shigley, J. E., and Mischke, C. R. (1989). Mechnical Engineering Design, 5th edition. McGraw Hill. ISBN 0-07-056899-5

Shuvendu patel 02:57, 30 March 2007 (UTC)==See also==