What is Volumetric Strain?
Channel: MechanicaLEi
Date: 2018-06-13

Welcome back MechanicalEI, did you know that Volumetric strain determines whether a block of cement can be used to fill a certain gap in a wall while taking into account temperature changes in the area? This makes us wonder, what is Volumetric Strain?Before we jump in check out the previous part of this series to learn about what elastic constants are? Now, Consider a rectanglular solid under stresses sigma 1, sigma 2 and sigma 3. Then epsilon 1, epsilon 2 and epsilon 3 will each denote the respective strain in their directions. The new dimensions of the rectangle become this. Volumetric strain then, is defined as the Increased volume of the rectangular solid upon the original volume of the solid and is denoted by theta. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (i.e. elastic + plastic) deformation begins. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Ultimate tensile strength is measured as the maximum stress that a material can withstand while being stretched or pulled before breaking. Some materials break very sharply, without plastic deformation, in what is called a brittle failure. Others, which are more ductile, including most metals, experience some plastic deformation and possibly necking before fracture. Hence, we first saw what Volumetric strain is, then saw what yield stress is and finally found out what ultimate stress is? In the next episode of MechanicalEI find out what Shear force and Bending Moment are?

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Doh De Oh by Kevin MacLeod is licensed under a Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/)
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Subtle Library by Fabian Measures (http://freemusicarchive.org/music/Fabian_Measures/) is licensed under a Creative Commons Attribution licence ( https://creativecommons.org/licenses/by/4.0/)
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