Tresca, Tresca Yield Criterion
						Index
		In about 1865 Tresca proposed a model for the onset of yield in a material under a general applied stress. He postulated that if the shear stress in any part of the body reached the yield stress associated with a uniaxial tensile or compressive load, the sample would start to plastically deform. This is known as the maximum shear stress criterion for yielding. The diagram shows the yield surface for an isotropic material that is a hexagonal prism passing through the origin of the principal stress space and arranged symmetrically about the hydrostatic line. Following the convention: s1 > s2 > s3 , the yield stress of the material under the multiaxial stress is:                   sy = (s1 - s3).