METHOD FOR PREDICTING CRITICAL BENDING RADIUS OF BUCKLING AT TIME OF BENDING HOLLOW SHAPE AND CROSS-SECTIONAL SHAPE OF HOLLOW SHAPE

摘要

PROBLEM TO BE SOLVED: To predict the critical bending radius of buckling before working at the time of bending. ;SOLUTION: In this predicting method of the critical bending radius of buckling, the cross-sectional shape of a hollow shape is divided into each plate element, the end part restraining state of parameter and each plate element with which the cross-sectional shape of the hollow shape is regulated is decided, stress state at the time of elasticity added to each plate element according to Bernoulli's hypothesis is decided, a buckling coefficient (k) is calculated according to the end part restraining state and stress state decided in the above mention. The critical stress σ_cr' of buckling of the objective plate element under the condition of 4-side support and pure compression is calculated based on the parameters of material properties used for shapes, real critical stress σ_cr of buckling of the objective plate element is calculated by multiplying the calculated critical stress σ_cr' of buckling by the buckling coefficient k/4 and the critical bending radius R_cr of buckling is calculated based on the critical stress σ_cr of buckling.;COPYRIGHT: (C)1999,JPO