Overall Stability Behaivor Of Q690GJ Welded H-shaped Section Beams

This thesis mainly investigated the global stability of Q690 high strength steel welded H-shaped beams.Total eight Q690 high strength steel welded H-shaped beam specimens were tested.Based on the experimental research,the finite element analysis(FEA)model was established by the FEA software ABAQUS to simulate the Q690 high strength steel welded H-shaped beam specimens.By using this FEA model,total 43 beam specimens were established to investigate the relationship between the key parameters and the stability bearing capacities.This thesis mainly conducted five parts including the introduction,the experimental research,the establish and validation of the finite element model,the parametric analysis,conclusion and prospect.The experimental research mainly including the material tests of the steel plates and the global stability tests of the beam specimens.Based on the test results of the global stability tests,the FEA model could be established and verified.Then,the parameter studies were conducted,and some important conclusions were found.The important conclusions were summarized and listed: Compared with current Chinese design code,the new versions of Chinese design code considered the effect of height-to-width ratio of the beam sections to the load carrying capacities of flexural members.And the results of this study shows that the load carrying capacity increases with the decline of the height-to-width ratio of the beam sections.In this article research is obtained by using the national standard of Q690 welding h-type section bearing capacity of flexural member overall stability,the elastic buckling of basic security components;And the prediction of calculate the elastic-plastic buckling by using the China 03 code may not be safe.Using the specification recommended formula for calculation of height to width is larger components,may not be safe.