Improved Scheme to Develop Multidimensional Generalized Yield and Failure Surfaces for Structural Elements

摘要

Techniques are developed and presented for combining readily available two-dimensional convex generalized yield and failure curves for structural elements to form lower bound, higher dimensional interaction surfaces. These higher dimensional surfaces are useful for predicting yielding or failure of structural elements when subjected to several simultaneously interacting generalized stresses at a given cross section. The work is an improvement on an earlier method that tended to be overly conservative. The earlier work is reviewed followed by the introduction of two improved methods, the first based upon the geometrical version of the Hahn-Banach Theorem, and the second based upon the use of Lagrange multipliers. Each method is illustrated by three- and six-dimensional examples, and the degree of conservatism of each is evauated by comparison to exact multidimensional interaction surfaces. (ERA citation 06:019061)