Types of Deformation
When a material is stretched, it gets a bit long. When the force is released, it may or may not return to the original shape, depending on the material and the force.
Take a long thin copper wire for example, hung from a support. Fix a load to the lower end, and the wire extends. Remove the load, and the wire returns to the original length. We call this elastic deformation.
Repeat the experiment with increasing load. Each time, the wire extends more than before. If the load is too big, the wire may not return to the original length. It could become a bit longer, even when the load is removed. The wire is permanently stretched. This is called plastic deformation.
Copyright 2010 by Kai Hock. All rights reserved.
Last updated: 2 October 2010.