磷石膏内置模空心楼盖静载试验研究与数值模拟

Static Load Test and Numerical Simulation of Hollow Floors with Phosphogypsum Built-in Module

为研究磷石膏内置模空心楼盖的静力特性,以肋梁是否加腋为研究参数,设计制作了2个全尺寸空心楼盖试验模型。通过对试验楼盖进行竖向分级加载,分析了楼盖挠度、钢筋应变随加载的变化情况,对比了肋梁加腋对楼盖静力性能的影响。采用有限元软件ABAQUS对空心楼盖进行数值模拟,详细地研究了钢筋应力、裂缝的发展变化过程,并对空心截面构造的剪力滞后效应进行分析。研究结果表明:肋梁加腋构造可降低空心楼盖跨中挠度,提升楼盖整体刚度,并且钢筋应变相对更小;空心楼盖受载时,首先在边梁跨中出现弯曲裂缝,楼盖应力重分布,随后板跨中区域开裂,并随着加载的继续,裂缝区域进一步扩大。此外,肋梁加腋构造可降低截面应力变化幅度,减轻应力滞后效应所带来的不利影响。

In order to analyze the static performance of hollow floors with phosphogypsum built-in module,two fullscale hollow floor test models of the rib beam which was haunched were designed and manufactured. The static load tests of the models were carried out by multistage loading. The changes of floor deflection and reinforcement strain with loading were analyzed,and the influence of haunch-adding of the rib beam on the static performance of the floor was compared. Through numerical simulation using ABAQUS,the development and change process of stress and crack were calculated,and the shear lag effect of the hollow section was analyzed. The results showed that the haunch-adding of the rib beam can reduce the mid span deflection of the floor,improve the stiffness of the floor,which makes the steel strain smaller. When the floor was loaded,the bending cracks appeared in the mid span of the side beam first,and then the mid span area of the slab was cracking due to stress redistribution,and the crack area expanded further with loading. Moreover,the haunch-adding of the rib beam can reduce the range of the stress and reduce the adverse effect of stress lag effect.