APPROXIMATE ESTIMATION OF HARDENING-SOFTENING BEHAVIOUR OF CIRCULAR PIPES SUBJECTED TO PURE BENDING

摘要

An approximate method for describing the plastic hardening-softening behaviour of circular pipes subjected to pure bending is presented.Theo-retical estimation based on the uniform ovalization model and local collapse modelproposed in the paper is incorporated to give several simple formulations with rea-sonable accuracy for determining the relationship between bending moment(M)andcurvature(k)in the purely bended pipes.Attention is focused on the critical cur-vature associated with maximum resistant moment and the maximum change in theoriginal diameter before the end of uniform ovalization stage as well as the localcollapse behaviour.Some comparisons between analytical results and experimentalresults are made in order to examine the theory.