基于步态分析技术的三向单足落步荷载曲线试验建模

Experimental investigation and mathematical modeling of single footfall load using motion capture technology

对单人步行荷载模型进行试验建模研究。采用三维动作捕捉技术结合三向(竖向、水平前进和水平横向)测力板,分两阶段开展100人次慢速、正常和快速3种自由行走以及1.5Hz、1.75Hz、2.0Hz及2.25Hz 4种固定行走频率工况的单人行走荷载试验。对试验所获得的2576组有效单足落步曲线进行统计分析,给出步频、步速、步长、双支撑比例以及荷载峰值比等控制参数的变化范围和分布规律,得到荷载峰值因子、单步时程持续时间与行走步频的统计函数关系。试验所得平均步长值较文献中常用值小。基于试验数据建立三向单足落步曲线的傅立叶级数模型,并给出由行走步频确定模型各阶动载因子以及相位角的取值方法。该荷载模型可用于人行桥、大跨度楼盖等工程结构在步行激励作用下的结构振动舒适度设计与分析。

The dynamic properties and walking load of Chinese people were studied based on experiments, The threedimensional motion capture technique in conjunction with three-dimensional force plates was employed in the test. There were two phases in the experiment, in which one hundred test subjects were involved. Each subject was evaluated and tested in seven cases, namely, three free-walking cases （with slow, normal and fast walking speed） and four fixed walking frequency cases （i. e. 1. 5, 1. 75, 2, 0 and 2. 25Hz）. Furthermore, 2576 reliable records of single footfall curves were statistically analyzed. Based on the experimental results, the variation range and probability distribution of several key parameters, such as stride frequency, walking speed, stride length and dynamic load factor, were obtained, An average stride length of O. 66m, which is shorter than the commonly used value of O. 75m, has been found in the test. A Fourier series model was then proposed to describe the single footfall load curve whose coefficients and phase angles are determined by the stride frequency. The experimental results can be utilized in the vibration serviceability assessment of long-span structures under human walking load.