A multidimensional anisotropic strength criterion based on Kelvin modes

A new theory for the prediction of multiaxial strength of anistropic elastoplastic materials is proposed. The resulting failure envelope, in a multidimensional stress space, is piecewise smooth. Each facet of the envelope is expected to represent the locus of failure data by a particular anisotropic elastic deformation mode called a Kelvin mode. It is shown that the Kelvin mode theory alone provides an incomplete description of the failure of some materials, but that this weakness can be addressed by the introduction of a set of complementary modes. A revised theory which combines both Kelvin and complementary modes is developed and illustrated by an applied example