Research on the Mechanical Response of a Bolt Connection by Experimental and Numerical Method

Abstract

For a mouth shaped strucure with bolt connection, the mechanical response and thread stress distribution were studied by experimental and numerical method. The structure was tested with variety of the pretension loads from 10 N.m to 70 N.m . In this paper, a numerical method modeling the helical thread was proposed. In the method, the structure was divided into three regions, thread region, conventional region and transition region. The conventional region was modeled with the conventional method, however, the thread region and the transition region were modeled using the Glide-Guide method. Firstly, two helical lines and the plane elements were created. Secondly, the plane elements were rotated along the lines, then the three dimensional elements for the helical model were obtained. Finally, the nodes of the transition region elements and the conventional region elements were merged so that the whole model was attained. The experimental structure was modeled by the method, and the mechanical response and thread stress distribution were obtained. The results show that the axial stress of the screw obtained by experiment and the numerical method were very close, and they were both close to the empirical formula when the equivalent friction coefficient was 0.22 . Comparing to the existing methods, the numerical method proposed in the article is mush simpler, and it can obtain reasonable results using all standard elements.