基于实物实验的地震下扶梯桁架后屈曲仿真分析
Simulation Analysis of Post-Buckling of Escalator Truss under Earthquake Based on Physical Experiment

为了评估自动扶梯桁架的安全性，对地震状况下建筑物层间变形所导致扶梯桁架压缩的力学特性进行了实验研究和仿真分析。首先，基于自动扶梯抗震标准的要求，进行了实物实验，获得扶梯桁架压缩变形形态和桁架支撑角钢水平支反力随压缩量大小的变化曲线。然后，通过采用多线性材料模拟扶梯桁架型材的塑性段应力–应变特性，并在分析中考虑焊缝和结构的桁架几何尺寸误差的影响，建立扶梯桁架精细化有限元模型，进行非线性后屈曲分析。结果表明，扶梯桁架仿真与实验的压缩变形方向和位置一致，桁架支撑角钢水平支反力随压缩量大小曲线趋势相同，其中压缩过程中的桁架支撑角钢最大水平和压缩后桁架的回弹量误差均小于5%，验证了所建立的精细化有限元分析模型的有效性，为自动扶梯的抗震分析提供参考。
In order to evaluate the safety of escalator truss, the mechanical properties of escalator truss com-pression caused by inter-story deformation of buildings in earthquake were studied experimentally and simulated. Firstly, based on the requirements of the escalator seismic standard, a physical ex-periment was carried out to obtain the compression deformation shape of the escalator truss and the change curve of the horizontal support reaction force of the truss support angle steel with the compression amount. Then, by using multi-linear materials to simulate the stress-strain character-istics of the plastic section of the escalator truss profile, and considering the influence of the weld and the geometric size error of the structure in the analysis, a refined finite element model of the escalator truss is established for nonlinear post-buckling analysis. The results show that the com-pression deformation direction and position of the escalator truss simulation are consistent with those of the experiment, and the horizontal support reaction force of the truss support angle steel with the compression process in simulation has the same trend with this of the experiment. The er-ror of simulation and experimental data of maximum horizontal reaction force of the truss support angle steel and the rebound amount of the compressed truss in the compression process are less than 5%, which verifies the effectiveness of the established refined finite element analysis model and provides a reference for the seismic analysis of the escalator.