Computational Method to Optimize Design of Gripping Part of Products via Grasping Motion Simulation to Maximize Gripping Comfort

Abstract

In this study, a grasping motion simulation method based on finite element analysis was developed for the virtual evaluation of gripping comfort while gripping a cylindrical object. The validity of the grasping motion simulation was verified by comparing the contact pressure distribution generated on the palm of a hand using a finite element model with the measured result obtained via experiments on a human subject. The mean absolute difference between the simulation and experimental results at 23 regions was 7.4 kPa, which was considered to be significantly low and an acceptable value for use in assessment of the gripping comfort score. Furthermore, topology optimization was introduced into the simulation to propose an easy method for obtaining a rough shape of the gripping part of a product that is comfortable to grip. An objective function during the optimization process was defined to minimize the contact pressure concentration level, and this was observed to have a negative correlation with the gripping comfort. The optimization result indicated low element density at the parts in contact with the tips of the index and middle fingers as well as high element density at the parts in contact with the proximal part of the palm. The method allows a designer to evaluate the gripping comfort of a product during the design process and aids in developing a shape that can provide better gripping comfort. Additionally, the method can also be used to reevaluate the gripping comfort of existing products.

Keywords

• gripping comfort
• finite element analysis
• hand model
• grasping motion
• contact pressure
• topology optimization