A novel approach to modelling and simulating the contact behaviour between a human hand model and a deformable object

Abstract

A deeper understanding of biomechanical behaviour of human hands becomes fundamental for any human hand-operated activities. The integration of biomechanical knowledge of human hands into product design process starts to play an increasingly important role in developing an ergonomic product-to-user interface for products and systems requiring high level of comfortable and responsive interactions. Generation of such precise and dynamic models can provide scientific evaluation tools to support product and system development through simulation. This type of support is urgently required in many applications such as hand skill training for surgical operations, ergonomic study of a product or system developed and so forth. The aim of this work is to study the contact behaviour between the operators' hand and a hand-held tool or other similar contacts, by developing a novel and precise nonlinear 3D finite element model of the hand and by investigating the contact behaviour through simulation. The contact behaviour is externalised by solving the problem using the bi-potential method. The human body's biomechanical characteristics, such as hand deformity and structural behaviour, have been fully modelled by implementing anisotropic hyperelastic laws. A case study is given to illustrate the effectiveness of the approach.

A first step in finite-element simulation of a grasping task

“…Implementing more complex material definitions (anisotropic hyperelastic three-dimensional materials) would be a straightforward extension of the present FE model. Although attempts have already been made, [24,42,43] it is still a big challenge. Friction effects play a key role in grasping task.…”

“…Gislason et al [23] studied the stability of the human wrist and the influence of additional constraints on the response of a FE model. Chamoret et al [24] explain the development of a three-dimensional FE model of the human hand and with a modeling of the contact between hand and a deformable object with complex constitutive anisotropic hyperelastic laws. The developed hand model is considered as biofidelic in terms of geometry which is based on three-dimensional reconstruction of CT scan images.…”

Functional design method for improving safety and ergonomics of mechanical products

“…At a numerical level, this gripping problem is very challenging because of the presence of strongly non-linear phenomena like contact between the hand and it environment, and hyperelasticity of the biological tissues [10]. The precise pressure map of the contacts and the dynamic change of these pressures are the critical focal point and computer aided simulation could provide a powerful tool to study contacts for many ergonomic centred studies for product, system and process development.…”

“…The directive imposes a maximum mechanical vibration level, in order to protect users from risks of musculoskeletal diseases. In order to check the entire family of the new pneumatic tools and to analyze very early on the design process the impact of vibrations, our self-developed digital biomechanical hand model will be applied [10]. Currently, this digital model is developed as stand alone model but its final goal is to simulate virtually its behaviour in interaction with digital mock-up of the product.…”

Fingertip finite element modelling – on choosing the right material property

“…Most of the existing models are based on hyperelastic laws (Wu 2002;Chamoret 2013); however, there is no consensus on whether using anisotropy or isotropy (only Chamoret used an anisotropic law). Fingertip complex shape could be simplified by idealised geometries such as ellipsoids (Wu 2002).…”