Test Research On Variable Amplitude Fatigue Behavior Of Grid Structure With Cross Plate--Welded Hollow Spherical Joints

With the many advantages of the embodiment of steel plant extensively in recent years. Particularly there aren't rules on the fatigue in《Specification for Design and Construction of Grid Structure》(JGJ7-91), so designers don't have references in fatigue design. That verily impacts the grid structure's application in the design method of fatigue.Based on fatigue test of grid structure with welded hollow spherical joints, the paper carries out the test on variable amplitude fatigue behavior of grid structure with welded hollow spherical joints and works out the following conclusions:1,Transformation designed a highly efficient,stable, reliable test loading device has been designed and commendably completed the variable amplitude fatigue test of all the specimens.2,Transformation designed cross plate-welded hollow spherical joints.3,The paper has acquired six cross plate-welded hollow spherical joint's variable amplitude fatigue test datas under program block through test research on variable amplitude fatigue behavior. 4,The paper has processed a comprehensive and systematic regression analysis on variable amplitude fatigue test data of the welded hollow spherical joints and pegs.5,This paper has introduced the "hot spot stress amplitude", and obtained the method of fatigue design for grid structure with the welded hollow spherical joints.6,This paper has analyzed some uncertain factors that have the greater influence on the fatigue test data.This paper improved the lack of pre-test ,the research results in the paper make up for the shortage of the test data of fatigue performance with cross plate-welded hollow spherical joints. The research results also can continue to supply referable data consult for the modification of《Specification for design and construction of grid structure》.