单人步行荷载竖向动力模型的比较研究

Comparative study on vertical dynamic models of single person walking load

大跨度梁板结构的人致振动已成为现代楼板结构体系设计中需要解决的常见问题,为准确评估此类结构的振动特性,需使用一个合理的步行荷载模型进行仿真。基于倒立摆模型(inverted pendulum model,IPM)、圆弧足底模型(rocker root model,RFM)和质量弹簧模型(spring mass model,SMM),通过大量模拟得到行人步频、平均步速、动载因子和质心运动轨迹等,并与已有的试验结果相对比,分别得到三种模型的真实输入参数取值范围。结果表明:IPM和RFM能较好地再现人体步态历程和质心竖向位移时程,且真实输入参数范围较宽,可用于研究人-结构竖向相互作用;SMM能够较为准确地描述行人步态历程和质心竖向位移时程,步行力时程曲线也与试验结果吻合,但该模型真实输入参数取值范围较窄,不适合用于研究人-结构相互作用。IPM、RFM可为柔性结构下考虑行人-结构相互作用的生物力学模型的建立提供参考。

Human induced vibration of long-span beam and slab structures is a common problem in modern floor system.In order to accurately evaluate the vibration characteristics of long-span soft structures,a reasonable walking load model should be selected.Based on IPM,RFM and SMM,the pedestrian step frequency,average step speed,first-order dynamic load factor and centroid trajectory were obtained through a large number of simulations.Compared with the previous research results,the accurate input parameters of the three models were obtained.The results show that the IPM and RFM can better reflect the human gait process and centroid trajectory,and the range of accurate input parameters is wide,which can be used to study the human-structure vertical interaction.The SMM can perfectly copy the gait process and centroid trajectory.The time history curves of walking force are also consistent with the experimental results.Because the real input parameters are narrow,it cannot accurately evaluate the vibration characteristics of the structure.The IPM and RFM provide a reference for the establishment of biological force model considering pedestrian structure interaction under flexible structure.