Study On Stability And Reliability Of Q345GJ Steel Welded H Section Flexural Members

GJ steel has been used on many important constructional projects in China becauseof its excellent combination property. While GJ steel failed to give full play to its ex-cellent performance due to there is no relevant provisions to guide its design. In order topromote the reasonable usage of GJ steel, based on the project of National NaturalScience Foundation of China (51078368)—Overall Stability Research of High per-formance GJ Steel Flexural Member Based on New material property, this thesis stu-died the overall stability and reliability of Q345GJ steel flexural member loaded atquartile.Material mechanical property test acquires the main mechanical properties ofQ345GJ steel, which provide basic data for finite element analysis. By the comparisonand exploration of several test setups, the research group designs a new kind of test se-tup that can eliminate the lateral restraint of loading device effectively. The experimen-tal study of4kind of section totaling8specimens examines the overall stability ofQ345GJ steel flexural members, and proves the reasonability of ANSYS FE model. Theexperimental results validate that the SHELL181FE model simulates Q345GJ steelflexural member well, so the35effective FEA results expand statistical data. Accordingto the41effective test data, the author acquired the resistance indeterminateness statis-tical parameter of Q345GJ steel flexural member, and hereby calculated and proposedresistance partial factor and design strength index by reliability analysis method basedon probability theory.From the current results, it can be found that the ultimate load-carrying capacity ofQ345GJ steel flexural members is higher than the calculation value of Code for Designof Steel Structures to some extent. When the target reliability index []is3.2, theproposed resistance partial factor Ris1.250(load combination without wind load, itcan be1.210) for GB50017-2003, and for GB50017-201X, it is1.045(no wind loadcombination, it can be1.015). While the target reliability index []is3.7, the pro-posed resistance partial factors Rrespectively are1.350(1.310) for GB50017-2003and1.125(1.095) for GB50017-201X.