The Research On The Local Stability Of Web Of Castellated Beams

Castellated beam is a new type of steel structure component,With reasonable section form,high bearing capacity,light in weight,beautiful and applicable,economic and many other advantages.It is applied more and more widely in the actual project.A row of holes on the web of castellated beams damage the continuity of mechanical properties and cut stress field.It is difficult to produce the post buckling strength of the web of castellated beam.At the same time,the boundary condition and transfer mode of the force of the web of castellated beam is also changed.So the mechanical properties have a great difference with the ordinary solid web steel beam.According to the stable theory of plate,the reference to the analysis methods and ideas of the stability of the web of steel beam.Taking the web of castellated beams as the object of study.Using the finite element method to analysis the elastic buckling action of the web of castellated beam with the hexagon hole in web under pure bend and under pure shear.The constraint function of the flange girth of castellated beam to web is considered.During the course of the research,Assuming that the boundary conditions of web of castellated beam is all four edges simply supported and two opposite edges simply supported and fixed.When the web of castellated beam is under pure bending and pure shear buckling modes of the web of castellated beam with the different holes parameters are described under two different boundary conditions.Many different parameters on the effect of elastic buckling bearing capacity are studied which are including the number of holes,diameter-depth ratio,space-depth ratio and depth-thickness ratio.Reference the calculation formula of the elastic buckling stress of the solid plate,Thecalculation formula of elastic buckling stress of the web of castellated beams with hexagon hole and different holes parameters and two kinds of different boundary conditions were fitted under pure shear basing on the result of finite element calculations.The constraint function of the flange girth of castellated beam to web is considered.The embedded solid factoris considered to measure the actual elastic restraint of the flange.The limit ratio of web height to thickness when subjected to pure bending or pure shear has derived.