开口截面钢-混凝土组合梁受扭的试验分析

为研究钢-混凝土组合梁在不同加载方式下的受扭性能,完成了6根钢-混凝土组合梁的弯扭试验和纯扭试验,其中2根梁的扭矩直接作用于工字钢梁上,其余4根梁则由钢梁和混凝土翼缘板作为整体共同受扭。试验结果表明,当扭矩直接作用于钢梁上时,混凝土翼缘板通过栓钉对钢梁的扭转提供约束,从而使钢梁的抗扭承载力比纯钢梁的提高2倍以上。在试验参数相同时,混凝土翼缘板和钢梁作为整体复合受扭时组合梁的开裂扭矩及极限抗扭承载力比扭矩直接作用于钢梁时的分别提高86%和39%。分析了两种不同加载方式下钢-混凝土组合梁受扭和受弯承载力的变化。建立了扭矩直接作用于钢梁上时极限扭矩的计算模型及计算公式。对整体受扭时组合梁的弯矩相关性进行了分析,并建立了相关曲线公式。计算结果与实测值吻合较好。

Experimental Analysis on Composite Steel-Concrete Beams with Open Section Under Combined Flexure and Torsion

In order to study the torsional behavior of composite steel-concrete beams under different types of applied torque,experiments have been conducted on six specimens subjected to to rsion and combined flexure and torsion,in which torque is applied to steel jois t directly for two beams and applied t o the composite section for other fou r beams.Test results show that torsional deformation is confined by concrete fla nge through stud shear connectors an d the torsional capacity of the beams with torque app lied to the composite section is abou t two times higher than that of the beams with torque applied to steel joist.The cracking torque and ultimate torque fo r composite section subjected to torsion are 86percent and 39percent higher than th ose of composite beams with torsion a pplied to steel joist respectively.Analysis is done on the flexural capacities and t orsional capacities for the beams under two types of applied torque.The a nalytical mode and the formulae are proposed fo r composite beams with torque applie d to steel joist.Analysis is also com pleted and the interaction curve is suggested f or the beams with torque applied to th e composite section.The predicted r esults are ingood agreement with the measured ones.