ULTIMATE DEFORMATION ANALYSIS OF FRAMED STRUCTURES UNDER VARIABLE REPEATED LOADINGS.

The paper presents a mathematical programming approach to the ultimate deformation analysis of flexural structures subjected to variable repeated loadings. By adding the residual deformations at shakedown load to the factored elastic deformations, the maximum elastic-plastic deformations, i. e. , ultimate deformations at the incipient structure collapse, can be found. While the residual deformation analysis of frames is formulated as a quadratic programming problem (OP) by using the Kuhn-Tucker condition, the linear programming (LP) approach permits the strength and deformation analyses to be performed at most three sequential LP applications. Several numerical examples are analyzed to illustrate the features and scope of application of this approach.