扁担挑物的动力学分析

DYNAMIC ANALYSIS OF A LOADED SHOULDER-POLE DURING WALKING

建立了扁担挑物的动力学模型和动力学方程,并进行了数值求解。扁担挑物时存在三种频率,即重物类似于单摆的振动频率、挑运者的步行频率和扁担-重物系统铅垂方向的振动频率。计算结果表明,为了获得较好的挑担体验,三种频率应该相互协调。当人挑担行走的频率为扁担-重物系统铅垂方向振动频率的70%~80%时,肩部铅垂附加动反力为重物重力的30%左右且与肩部铅垂运动同相,当重物类似于单摆的振动频率为人步行频率的25%~30%时,重物的摆角和肩部受到的水平附加动反力均较小,从而有利于人挑担行走。

A dynamic model and the related equations for a loaded shoulder-pole during walking are established.Three frequencies are involved, i.e. the vibration frequency of the load simplified as a pendulum, the walking frequency and the vertical vibrant frequency of the loaded shoulder-pole. Numerical calculation results indicate that in order to make the walking comfortable, the above three frequencies should be coordinated. When the walking frequency is 70% ~80% of the vertical vibrant frequency of the loaded shoulder-pole, the vertical additional dynamic reaction force on the shoulder is about 30% of the weight of the load and is in the same direction with the vertical moment of the shoulder. When the vibration frequency of the load simplified as a pendulum is 25% ~ 30% of the walking frequency, the swing of the loads and the horizontal additional dynamic reaction force on the shoulder are relatively small.