Load and Stress Distribution of Thread Pair and Analysis of Influence Factors

Abstract

Analyzing the axial load(axial force) distribution and the stress distribution of the root of the thread is helpful for accurately predicting the thread failure and optimizing the design of the structure of the nut and the bolt. The existing research mainly analyzes the axial load distribution and stress distribution of the thread by using the two-dimensional(2D) finite element model(FEM), and they have no theoretical support. In this paper, a three-dimensional(3D) finite element model was established, and a theoretical model of the stress calculation of the root of the thread was established. The theoretical calculation results of this paper were compared with the results of the 3D finite element model analysis. The results show that the two are in good agreement with each other, which verifies the consistency between the theoretical model and the 3D finite element model. Then, the stress of the root of the bolt and nut is investigated under the action of axial force. And the factors, such as Young's modulus E, axial total load F, friction coefficient μ, radial thickness H, engaging threads number N, thread defect which affect the load distribution are systematically studied.