Stress Analysis of a Bolt-Nut Joint by the Finite Element Method and the Copper-Electroplating Method : 1st Report, Stress at the Root of a V-Grooved Rod under a Tensile Load

Abstract

There are many studies on the stress at the root of a loaded bolt thread which is screwed in a nut thread, but most of them are being based on the two dimensional analysis. This paper presents a three dimensional analysis of a bolt-nut joint by the finite element method and Okubo's copper-electroplating method. In the 1st report, such two methods of analysis are applied to a V-grooved rod under a tensile load as the first step. Firstly, the numerical solution of the stress concentration factor by the finite element method is computed by an electric digital computer. Secondly, a high accurate measuring method of the stress concentration factor of the V-groove by the copper-electroplating method is presented. These two methods of analysis are applied to V-grooved rods having three kinds of root radius, and the results are compared with each other. They show good agreement, but the value by Neuber's method is smaller than those two values.