Abstract
This paper deals with a practical method for calculating the local buckling strength of the outstanding plates as a part of columns or girders. Many reserches concerning such problems in specific boundary conditions have been published up to now, but little has been worked out in simplified formulas applicable for practical design. Exact relations among the stability coefficient, rigidity of the longitudinal edge stiffener and restrictive modulus of bending at built-in edge are very troublesome. Formulas for structural purposes in a variety of applications are proposed herein derived from an approximate method based on consideration of the energy of the system, and expressible in the form; [numerical formula] where [numerical formula] k=stability coefficient of the rectangular plate with one edge parallel to direct stress elastically built-in and opposite edge supported elastically by longitudinal stiffener. β=a/b=length to width ratio a=length of plate b=depth of plate t=thickness of plate J=moment inertia of longitudinal stiffener v=poisson's ratio E=modulus of elasticity δ=F/bt F=sectional area of stiffener C=restrictive bending moment per unit length and rotation at built-in edge The minimum value of k is [numerical formula] For the numerical application of the proposed formula, several cases having various end conditions are presented. In the case of lip channel section of uniform thickness such as light gage steel, local buckling load of the flange plate may be calculated substituting C=d/2b in the formula where d=depth of web plate.
