Convexity restrictions on non-quadratic anisotropic yield criteria
Examination of \textit{R. Hill}'s anisotropic yield criterion [Math. Proc. Camb. Phil. Soc. 85, 179-191 (1979; Zbl 0388.73029)] shows that for Cases I, II and III, there are combinations of m and R for which the yield loci are outwardly concave or even unbounded. For Case I, all loci are concave unless \(m=2\). For Cases II and III, the combinations of m and R which lead to concavity and unboundedness have been established. Case IV and Hosford's criterion have no problem regions as long as \(m\geq 1\).
scientific article; zbMATH DE number 4020570