分片装配式楼梯试验研究及有限元分析

Experimental study and finite element analysis on sliced prefabricated staircases

为研究分片装配式楼梯的受力性能及分片楼梯之间抗剪销对其整体性能的影响,对3个足尺试件进行楼体单元的静力加载试验,包括半片楼梯单独加载和双片楼梯同时加载。介绍了楼梯构造、试验装置及加载方案;试验得到了楼梯的破坏模式、荷载-位移曲线、荷载-应变曲线及受力特性。在此基础上,采用ANSYS建立了非线性有限元模型,有限元计算结果与试验结果吻合良好。研究结果表明：荷载施加至楼梯正常使用极限状态所要求的跨中挠度时,楼梯钢筋均未屈服;半片楼梯加载时,所得承载力很接近双片楼梯同时加载的承载力,且均为单片楼梯承载力的2倍。有限元分析结果表明：当布置3根抗剪销时,两片楼梯挠度差很小,可忽略;当两端抗剪销对称布置在第5台阶（3l/10）时,3根抗剪销截面剪力分布较均匀,此种布置更合理;当布置2根抗剪销时,两片楼梯挠度差受抗剪销位置的影响较大,当2根抗剪销对称布置在第6台阶（9l/25）时更合理。

To study the mechanical performance of the sliced prefabricated staircase and the influence on the whole performance of the staircase from shear pin,three full-scaled specimens were tested statically,including half and two staircases under loading. The staircase construction,test instrument and scheme were presented in detail,and through analyzing the test results,failure mode,load-displacement curve,load-strain curve and mechanical performance of the experimental staircases were obtained. On this basis,the nonlinear finite element models were established by using ANSYS. The experimental results are in good agreement with the results of the finite element. The research indicates that the steel does not yield when the mid-span deflection of staircases under loading reaches the limit in serviceability limit state. The bearing capacity of half staircases is very close to whole staircases under loading,which is twice as much as that of single one. The finite element analysis results show that the deflection difference between two stairs with three shear pins is very small,which can be ignored. The shear pins of ends arranged symmetrically in the fifth step of stairs（ 3 l/10） are more reasonable as the shear of pins distributed more evenly. The shear pins arranged symmetrically in the sixth step of stairs（ 9 l/25） are more reasonable because the position of shear pins has great impact on deflection difference between stairs with two shear pins.