弹性转动约束的钢-混组合梁腹板剪切屈曲试验研究

Experiment on wed buckling in steel-concrete composite girder considering elastic rotational restraint boundary under shear

基于里兹能量法与弹性板件理论推导钢-混组合梁腹板弹性转动约束系数χt计算公式与边界弹性转动约束的腹板剪切临界屈曲应力计算公式。由计算公式可知,钢-混组合翼缘弹性转动约束系数χt的主要影响因素为剪力钉的纵向间距s与横向间距li,且翼缘的弹性转动约束对腹板剪切临界屈曲应力有决定性影响。为验证弹性转动约束系数χt与腹板剪切临界屈曲应力计算公式,进行了一组7片钢-混组合梁试验,考察组合翼缘剪力钉布置的纵向间距s、横向间距li两个变量对腹板弹性转动约束系数以及临界屈曲应力的影响。通过对组合试验梁结果与该文理论方法计算的边界弹性转动约束的腹板临界屈曲应力结果进行比较,发现两种结果变化趋势一致,误差不超过11.6%,验证了之前提出的计算公式的正确性。

Rotational restraint coefficient formula of steel-composite boundary and local buckling critical coefficient formula under shear of steel- concrete composite beam webs considering the rotationally restrained were deduced based on the Ritz variational method and plate buckling theory. The rotational restraint coefficient X in web of steel-concrete composite girder, influenced by the longitudinal spacing distance s of shear stubs and transverse spacing distance li, plays an important role in the local buckling critical coefficient of webs. 7 steel-concrete girders were tested, in which longitudinal spacing distance s of shear stubs and transverse spacing distance Ii were changed to verify the rotational restraint coefficient formula and local buckling critical coefficient formula considering the rotationally restrained. The theoretical and experimental results agreed well with each other, which proved the effectiveness and correctness of the proposed method.