Research On Fatigue Failure Mechanism And Influencing Factors Of Grid Structure With Welded HSJ

Welded hollow spherical joints are the earliest used kind of joints in our country, and are widely used for their simple structure. The problem of fatigue in welded hollow spherical joints would be concerned by engineers and scientists when the grid structure with hanging crane is widely used in industrial building. The fatigue test is the most useful and reliable method in fatigue research.Based on fatigue test of grid structure joints, A highly efficient,stable, reliable test loading device and welded hollow spherical joints had been designed, and We get 20 fracture sections. In this paper, a lot of macro and micro fracture sections are analyzed on pipe-welded hollow spherical joints and cross plate-welded hollow spherical joints by use of scan-electronic microscope. Its fatigue mechanism was known fundamentally. At the same time, the influencing factors of fatigue failure are summerised according to test data and theory analysis.This paper ,according to the research of fatigue test of grid structure under the hoisting crane, was valuable to establish fatigue calculation method.