A Calculation Method of Overall Stability for Flat Plate Stiffened Panels Under Compression

Flat panel stiffened plates are the basic components of steel box, steel tower and steel arch in steel structure bridges. In order to study the overall stability of flat panel stiffened plates, the finite element models verified by experiments were established for overall stability analysis. The effects of different constitutive relations, initial geometric defects and welding residual stresses on the overall stability bearing capacity were considered. It was found that: the ideal elastic-plastic constitutive model could be used to safely analyze the overall stability of flat plate stiffened panel under compression. Increasing the initial bending amplitude and loading eccentricity of the model would weaken the plates' overall stability capacity. When the defect amplitude was 1/1 000 of the calculated length, the bearing capacity of model initially bent on the side of the plate rib was relatively low, but the model initially bent on the side of the stiffened plate was more sensitive to the defect; increasing the peak value of welding residual compressive stress would reduce the overall axial stiffness and ultimate average stress of flat plate stiffened panels. Within the range of the relative slenderness ratio studied, the fitted calculation formula curve was lower than the test value and the curve of equal strength steel u-rib column, and was generally close to the class B column curve in the <italic>Specifications for Design of Highway Steel Bridge</italic> (JTG D64—2015), higher than the column curve corresponding to the Japanese and American codes, which could be safely used for the overall stability calculation of flat panel stiffened plates.