The stress function basis of the upper bound theorem of plasticity

The discontinuous slip-line form of upper bound plasticity analysis is considered using an equilibrium forces approach. It demonstrated that the underlying basis approach can be written in terms stress functions provide a continuum state interpretation solution. An alternative proof theorem, applicable to both associative and non-associative materials, presented. broader nature strict conditions under which it valid are discussed, including examination apparent omission moment associativity many solutions. Finally, relationship function formulation output computational limit method discontinuity layout optimisation (DLO) potential use derive lower solution from demonstrated.