LAUSR

Corrugated steel web is folded along the longitudinal direction and has the mechanical properties such as axial compression stiffness corrugation effect, shear modulus corrugation effect, similar to that of an accordion. In order to study the lateral-torsional buckling of box beams with corrugated steel webs (BBCSW) under the action of bending moment load, the neutral equilibrium equation of BBCSW under the action of bending moment load is derived through the stationary value theory of total potential energy and further, along with taking Kollbrunner-Hajdin correction method and the mechanical properties of the corrugated web into consideration. The analytical calculation formula of lateral-torsional buckling critical bending moment of BBCSW is then obtained. The lateral-torsional buckling critical bending moment of 96 BBCSW test specimens with different geometry dimensions are then calculated using both the analytical calculation method and ANSYS finite element method. The results show that the analytical calculation results agree well with the numerical calculation results using ANSYS, thus proving the accuracy of the analytical calculation method and model simplification hypothesis proposed in this paper. Also, compared with the box beams with flat steel webs (BBFSW) with the same geometry dimensions as BBCSW, within the common range of web space-depth ratio and web span-depth ratio, BBCSW’s lateral-torsional buckling critical bending moment is larger than that of BBFSW. Moreover, the advantages of BBCSW’s stability are even more significant with the increase of web space-depth ratio and web depth-thickness ratio.摘要波纹钢腹板沿纵向呈褶皱状, 具有轴压刚度波折效应及剪切模量波折效应等力学特性。为研究 弯矩荷载作用下波纹钢腹板箱形梁(BBCSW)的侧扭屈曲, 在考虑Kollbrunner-Hajdin 修正方法及波纹 钢腹板力学特性基础上, 利用势能驻值原理推导出BBCSW 在弯矩荷载作用下的中性平衡方程, 并进 一步获得BBCSW 屈曲临界弯矩解析计算公式。利用本文提出的解析计算方法及ANSYS 有限元方法 对96 个不同截面几何尺寸及计算长度的BBCSW 模型的临界屈曲弯矩进行计算。结果表明: 本文解 析计算结果与ANSYS 有限元数值计算结果吻合良好, 论证了本文解析计算方法及模型简化假设的合 理性; BBCSW 与普通钢腹板箱形梁(BBFSW)在同等几何尺寸的情况下, BBCSW 可取更小的腹板厚 度而无需加劲肋, 从而降低工程造价。在腹板距高比和腹板跨高比的共同范围内, BBCSW 侧扭屈曲 临界弯矩大于BBFSW, 而且, 随着腹板距高比和腹板跨高比的增加, BBCSW 的稳定性优势更加显 著。