Dong Ren G, Welcome Daniel E, Wu John Z
Engineering & Control Technology Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, West Virginia 26505, USA.
Ind Health. 2005 Jul;43(3):485-94. doi: 10.2486/indhealth.43.485.
The hand-tool coupling force in the operation of a vibrating tool is generally composed of applied force (AF) and biodynamic force (BF). There is wide interest in quantifying the coupling force. The objectives of this study are to develop an effective method for estimating the BF and to investigate its fundamental characteristics. Using the biodynamic response of the hand-arm system, such as apparent mass or mechanical impedance, and the acceleration that can be measured on vibrating tools, this study proposed an indirect method for the BF estimation. The BFs distributed on the fingers and the palm of the hand along the forearm direction (z(h)-axis) in the operations of eighteen types of tool were estimated and used to identify the distributed BF characteristics. The results indicate that the BFs depend on both the tool vibration spectrum and the biodynamic properties of the hand-arm system. The dominant BF frequency component is usually at the same frequency as the dominant vibration frequency of each tool. The BF distributed on the palm (2-98 N) is much higher than that distributed on the fingers (1-30 N) at frequencies less than 100 Hz, but these biodynamic forces (2-22 N) are comparable at higher frequencies. The palm BF on several tools with relatively low dominant frequencies (< or = 40 Hz), especially in the resonant frequency range (16-40 Hz), is comparable with the applied palm force (50-100 N). Since the resonant frequency of the palm BF is also in the range of the dominant vibration frequencies of many percussive tools, the palm BF may be related to the disorders in the wrist-arm system. The BF on the fingers is likely to be closely related to the dynamic stresses and deformations in the fingers and it may thus be used to quantify the finger vibration exposure.
振动工具操作中的手动工具耦合力通常由作用力（AF）和生物动力（BF）组成。人们对量化耦合力有着广泛的兴趣。本研究的目的是开发一种有效的方法来估计生物动力，并研究其基本特性。利用手臂系统的生物动力响应，如表观质量或机械阻抗，以及可在振动工具上测量的加速度，本研究提出了一种间接估计生物动力的方法。估计了18种工具操作中沿前臂方向（z(h)轴）分布在手指和手掌上的生物动力，并用于识别分布的生物动力特性。结果表明，生物动力既取决于工具振动频谱，也取决于手臂系统的生物动力特性。生物动力的主要频率成分通常与每种工具的主要振动频率相同。在频率低于100Hz时，分布在手掌上的生物动力（2 - 98N）远高于分布在手指上的生物动力（1 - 30N），但在较高频率下，这些生物动力（2 - 22N）相当。几种主导频率相对较低（≤40Hz）的工具，尤其是在共振频率范围（16 - 40Hz）内，手掌生物动力与施加的手掌力（50 - 100N）相当。由于手掌生物动力的共振频率也在许多冲击工具的主导振动频率范围内，手掌生物动力可能与手腕 - 手臂系统的紊乱有关。手指上的生物动力可能与手指中的动态应力和变形密切相关，因此可用于量化手指的振动暴露。
