Integral Mean of Yield Criterion in Design and Fitness for Service Assessment

Mura’s variational formulation for determining limit loads, originally developed as an alternative to classical methods, is extended further by allowing the pseudo-elastic distributions of stresses to lie outside the yield surface provided they satisfy the “integral mean of yield” criterion. Consequently, improved lower-bound and upper-bound values for limit loads are obtained. The m_α estimation limit load method, reference volume method and the fitness for service assessment procedure (including corrosion damage and thermal hot spot damage), are all applications and extensions of the “integral mean of yield” criterion.