鉄骨充腹ばりの横座屈に関する研究(その3) ―任意曲げモーメントを受けるH形断面ばりの横座屈荷重の数値解析―

Abstract

Lateral buckling phenomenon is one of the most important factors to determine the maxsmumload carrying capacity of H-shaped beams. This paper presents the results of numerical analysisof the elastic lateral buckling load of H-shaped beams under various types of bending moments;unequal end moments, bending moments due to uniformly distributed load and combined mo-ments of these two. Generally, partial differential equations in equilibrium condition are impos-sible to solve analytically. In this paper, basic equations are replaced by finite difference equations.Lateral buckling load is obtained as the load at which the stiffness matrix of the beam becomessingular. As the results of analysis, it is observed that the acting location in vertical direction ofuniform load significantly affects upon the lateral buckling load. Non-dimensioned bucklingload is quasi-linear to the span length of beams. On the other hand, it is also confirmed thatthe lateral buckling load of the beams subjected to not only end moments but uniformly dis-tributed load, is given as a very complex function of dimension of cross-section, end moment ratio(α), magnitude of uniformly distributed load (β) and span length (L). Appropriate formulationfor design is urgently needed considering the combination of the above-mentioned factors.