橡胶-焊钉组合连接件对钢-混组合梁受力性能影响分析

Mechanical Analysis of the Influence of Rubber-Sleeved Stud Connector on the Steel-Concrete Composite Girder

为了研究橡胶-焊钉组合连接件力学性能及其对组合梁受力性能的影响,设计制作了5组15个推出试件,通过静力加载试验测试了橡胶-焊钉组合连接件的受力性能,并采用有限元模型针对组合焊钉连接件对于组合梁受力性能的影响进行了分析。试验及有限元分析结果表明:组合焊钉连接件在不改变推出试件承载能力的情况下有效减小了试件的抗剪刚度,且橡胶-焊钉组合连接件对连续组合梁挠度以及钢梁应力的影响很小,但对中支点位置的混凝土应力降低作用明显。对于布置直径为22和19 mm焊钉的组合梁桥,采用组合连接件后组合梁负弯矩区混凝土应力降低比例可达26%以及13%。针对刚度变化位置产生较大的应力突变问题,在正弯矩区与负弯矩区的交接部分设置2 m的过渡区域能够使应力突变大小减小30%,有效改善了变刚度区域应力突变的现象。

To study the mechanical properties of the rubbersleeved stud connector and its influence on the steel-concrete composite girder,5 groups of 15 push-out test specimens are designed and fabricated.The mechanical behavior of the rubber-sleeved stud connector is revealed by using the static loading test while the influence of the rubber-sleeved stud connector on the steel-concrete composite girder is analyzed by using the FEM(finiti element method)models.The test and finite element analysis results show that the rubbersleeved stud connector helps to reduce the shear stiffness of the push-out test specimens without decreasing the carrying capacity.Meanwhile,the rubber sleeve has little impact on the mid-span deflection and the stress in the steel girder but magnificently decreases the stress in the concrete slab at the mid-support.For composite bridges using shear connectors with a diameter of 22 mm and 19 mm,the tensile stress in concrete slab decreases by 26%and 13%respectively.As for the problem of sudden stress change,a transition area of 2 m at the intersection of the positive moment region and the negative moment region can reduce the stress mutation by30%,which effectively improve the adverse condition in the stiffness changing region.