Study On The Bulking Modes And Its Influence Factors Of Stiffened Plate Under Axial Compression

Stiffened steel plates are widely used in bridges because of its high strength and low self weight.The elastic buckling always cause the waste of material strength,owing to that before the material reach its ultimate strength,the stiffened plate already collapse because of elastic buckling.Thercfore,the study on buckling of stiffened pl.ate is very necessary.Using the constrained finite element method,the proportions and trends of three buckling modes(Global buckling,distortional buckling and local buckling)varies with the changes of numbers of stiffeners,distance between stiffeners and stiffeners'size were studied.Firstly,the analytical solutions of rectangular plate without stiffeners in many different boundary and load conditions were calculated.Then,using constrained finite element method and FEM software,the critical buckling loads were obtained.The errors of constrained finite element method were basically below 1 ×10-3,which were lower than,that of FEM software.Thus,the reliability of constrained finite element method was proved.Secondly,the definition,criteria and buckling shape of three buckling modes,which can describe the buckling shape precisely,were clarified.Based on the criteria,the background and theory of modal identification and modal analysis methods:(regular)method,(GB+DB+LB)method,(GB+DB)method were explained.Using these methods,the proportions and trends of three buckling modes,the buckling stress and buckling shape of stiffened plate varies with numbers of stiffeners and stiffeners'size were studied.Finally,three important parameters,numbers of stiffeners,distance between stiffeners and stiffeners'size,were picked.By variable-controlling method,the relationship between the proportions of buckling modes and these parameters were studied.Eventually the correlations of the proportions of buckling modes and these parameters were founded.