Abstract
This is a review-note on uniqueness and stability criterions in incremental theory of plasticity. A simple truss consisting of two members is introduced as a model structure for expanations of the theory. A sufficient condition of uniqueness is given as follows: [numerical formula] Where l_i, N_i, e_i, α_i, denote length, axial force, elongation and rotation angle of the i th member, respectively, ⊿ denotes the differences of the quantities corresponding two different virtual modes, and ・ denotes d/dt. A sufficient condition of stability is also given as follows: [numerical formula].
