Estimation of stress field near a notch root of 3-D structures with a few strain data and the body force method

A method is proposed for estimating stress fields using a few surface strain data, obtained either from strain gages or from finite-element analysis (FEA), and the body force method (BFM). A notch in a three-dimensional structural surface is considered to be an observed domain. The observed domain is treated as a pseudo-3-D plate, not a part of a 3-D body. In other words, the body force is distributed in the observed domain to add a 3-D influence to a plane stress problem. In this paper, the results by elastic finite-element method (FEM) analysis are used instead of the strain gage outputs on actual structures to investigate the application limit of the present method. It is possible to obtain the maximum stress value within 10% error by self-assessment of the result with the present method.