G030072 ひずみゲージと解析関数による大たわみ問題の応力場推定に関する研究

Abstract

This study aims to estimate of stress fields of real notched plates that are subjected to large out-of-plane deflections. The general solutions of von Karman equations on this problem does not exist, therefore the authors try to estimate a stress fields of large deflection problem by superposing stress fields of two soluble linear problems, a bending problem and a plane problem. This paper provides the approximate procedure to estimate of stress fields in a circular-holed plate subjected to large out-of-plane deflections using strain gages and the equations on stress fields near a notch root in a plate subjected to out-of-plane bending and in-plane deformation. Unknown coefficients of the equations are determined by the stress values from rosette-type strain gages using the method of least squares. The rosette-type strain gages are located on circular arc whose radius is 1.5 times the notch root radius. The estimated maximum stress values at a notch root are compared with those by the finite element analyses. The estimated results are approximate to those by the finite element analyses in the cases when the ratio of the maximum deflection to the plate thickness is less than 0.8. In these cases, the membrane stress is large enough for problems of large deflection.