Simulation of the deformation and stress distribution within a flexible material pressed by a pinch gripper

A finite element simulation model has been developed for a pinch gripper pressing a non-rigid materials (NRM) predicting deformations and stresses occurring within the material. Specific attention is given to the differences in response of NRMs to two types of gripper (rectangular gripper and cylindrical gripper). The influence of mesh refinement and aspect ratio of the elements has been studied. The non-linear behaviour of NRM compression has been described in the materials model used by the FE program. Experiments have been carried out to validate the FE modelling approach for a specific material sample (polyurethane (PU) foam). It is concluded that there is a good comparison between the modelling and experimental results and that model gives a reasonable prediction of what could happen in the real case. The advantages of this model are ease of construction, fast solution times and good accuracy. This research could be benefit gripper design, and provide a better understanding of grasping mechanism of robotic pinch gripper.