Abstract: In the case of pure bending, a well-defined calculation formula exists for the buckling stress of I-shaped girders composed of flanged corrugated steel web (referred to as I-shaped CSW girder). However, this formula is not applicable under non-pure bending conditions. Numerical simulation study on cantilevered I-shaped CSW girders subjected to concentrated loads at the free end was carried out. The results indicate that the I-shaped CSW girder exhibits three kinds of buckling modes such as flange buckling, web buckling, and coupled buckling. When the buckling of the girder is dominated by the buckling of the flange plate, the buckling stress of the cantilever non-pure bending girder is greater than that of the pure bending girder. In this case, the width-to-length ratio of the flange is the primary factor influencing the buckling stress of the flange plate. Combined with numerous numerical simulation results, the buckling coefficient of the flange plate was revised and a formula for calculating the buckling stress of I-shaped CSW girder was proposed, which covered all buckling modes.

Key words: bridge engineering; I-shaped CSW girder; flange buckling; web buckling; coupled buckling; width-to-length ratio

摘要： 纯弯条件下，带钢翼缘板的波形钢腹板I形组合梁（简称I形波板梁）的屈曲应力已有明确的计算公式，但该公式不适用于非纯弯的条件。笔者对自由端受集中荷载的悬臂式I形波板梁进行了数值模拟研究，结果表明：该种梁有3种屈曲模态，分别是翼缘板屈曲、波板屈曲和耦合屈曲；当梁的屈曲由翼缘板屈曲主导时，悬臂式非纯弯梁的屈曲应力大于纯弯梁的屈曲应力，此时翼缘板的宽长比为影响翼缘板屈曲应力的主要因子；结合大量的数值模拟结果，笔者对翼缘板屈曲系数进行了修正，提出了涵盖全部屈曲模式的I形波板梁屈曲应力计算公式。

关键词: 桥梁工程；I形波板梁；翼缘板屈曲；腹板屈曲；耦合屈曲；宽长比