The Hanging Point Of The Spatial Grid Structure High Strength Bolt Fatigue Test Research

In recent years, the advantages of light weight steel structure with its widely used in long-span space truss structure industrial workshop. Unlike traditional bridge crane, space truss structure plant can use suspension crane, so dynamic loading fatigue problem worthy of further study. The fatigue of the space truss structure including:structure component fatigue, tired of hanging lifting point. At present, the fatigue test is the most reliable research method. Based on the national natural science foundation project-space truss node fatigue test as the background, main research space truss structure of hanging point of high strength bolt fatigue damage problem, the research content including:1、Using ANSYS software to the hanging point of high strength bolts in finite element simulation analysis, observation under the effect of unilateral axial tensile force, the stress distribution of high strength bolt, and calculate the stress concentration factor in thread.2、Hanging point is obtained by fatigue test, the M36variable amplitude fatigue data of high strength bolt.3、Sorting data and combining with the existing other type high strength bolt s-n curve equation, obtained the M36equivalent stress amplitude and variable amplitude fatigue and to fitting, get the new s-n curve. 4、Will test the high strength bolts, macro and micro fracture, metallographic analysis reveals that the fatigue fracture caused by stress concentration, and illustrates the three stages of fatigue fracture.In this paper, test data can be acquired in order to further establish the hanging point of the spatial grid structure, high strength bolt luffing fatigue design method and the fatigue life estimation method to lay the foundation.