A MIN-MAX PROCEDURE FOR THE SHAKEDOWN ANALYSIS OF SKELETAL STRUCTURES

A solution procedure for elastic-plastic structures subjected to variable repeated loads is elaborated using a min-max formulation of the shakedown problem. This optimization procedure performed in a multi-dimensional space of parameters is transformed and further reduced to a solution of a set of algebraic equations and a one-dimensional minimization problem. To this purpose use is made of relationship between statically admissible residual stresses and plastic strains. The latter, treated in the analysis as free parameters, provide at the end of the optimization process some additional information on possible residual displacements prior to shakedown. Illustrative examples of space frames are presented to show the accuracy of the proposed procedure.