Modeling of the biodynamic responses distributed at the fingers and palm of the hand in three orthogonal directions

Abstract

The objectives of this study were to develop models of the hand-arm system in the three orthogonal directions (x h , y h , and z h ) and to enhance the understanding of the hand vibration dynamics. A four-degrees-of-freedom (DOF) model and 5-DOF model were used in the simulation for each direction. The driving-point mechanical impedances distributed at the fingers and palm of the hand reported in a previous study were used to determine the parameters of the models. The 5-DOF models were generally superior to the 4-DOF models for the simulation. Hence, as examples of applications, the 5-DOF models were used to predict the transmissibility of a vibration-reducing glove and the vibration transmissibility on the major substructures of the hand-arm system. The model-predicted results were also compared with the experimental data reported in two other recent studies. Some reasonable agreements were observed in the comparisons, which provided some validation of the developed models. This study concluded that the 5-DOF models are acceptable for helping to design and analyze vibrating tools and antivibration devices. This study also confirmed that the 5-DOF model in the z h direction is acceptable for a coarse estimation of the biodynamic responses distributed throughout the major substructures of the hand-arm system. Some interesting phenomena observed in the experimental study of the biodynamic responses in the three directions were also explained in this study.

A Sequential Approach to the Biodynamic Modeling of a Human Finger

“…A direct comparison with other research proved difficult due to the lack of detailed finger data, but the ranges of the stiffness and damping were analyzed. The translational stiffness values are lower in comparison with those obtained by other researchers (e.g., [3,19,20]), and the damping is also lower for the distal and middle phalanx and comparable for the proximal phalanx. The reason for different value ranges is mainly due to the scale of the finger-measurements data that were used for the modeling.…”

“…The speed and stability of the computational algorithm and the validity of the obtained model results depend on suitable constraints for the searched model parameters [20]. Due to the lack of sufficient single-finger damping and stiffness data, it proved difficult to determine the exact damping ( , ) and stiffness ( , ) constraint ranges.…”

“…However, until recently, only the biodynamic response of the entire hand has been measured; 2 Shock and Vibration therefore, researchers have been developing whole hand-arm models with limited focus on the hand's subparts (see reviews [15,16]). As the biodynamic-response method improved, however, Adewusi et al [17] and Dong et al [18,19] started focusing on separate palm and fingers models, which were also upgraded for all three orthogonal directions [20]. The fingers in these models are represented only simply: only one or two lumped-mass elements are used for all five fingers.…”

“…These models focus on specific details of the finger, for example, stress/strain distributions in the fingertip, modeling of the soft tissue, bone, and nail, and the tactile discrimination test, and not on the biodynamic response of all the fingers. A major downside of finite-element finger models is that developing a sufficiently experimentally validated FE model is a challenging research task and FE modeling is also both expensive and time-consuming [20].…”

Differences in energy flow in three directions in Human-Tool biomechanical systems based on spatial human physical models specified in the ISO 10068:2012 standard

“…The fact is that work on the development of new models (ISO 10068:2012) has been conducted for a few years and presented in numerous publications, e.g. (Dong et al, 2007(Dong et al, , 2010(Dong et al, , 2013. Models described in the withdrawn standard ISO 10068:1998 have also been verified and approved and have been in use all over the world for many years.…”