Deformation Analysis Of Silicone Rubber Finger Based On Absolute Nodal Coordinate Formulation

Silicone rubber fingers are one of the key components that constitute modern new flexible robots and flexible manipulators.Accurate modeling of silicone rubber fingers is an important research direction.Different silicone rubber fingers have different structural forms,different materials hardness and different driving methods,and the overall deformation is large,making accurate modeling difficult.The absolute nodal coordinate formulation(ANCF)is suitable for calculating large deformation and large displacement,and many scholars use it to analyze large deformation and large displacement.In this paper,the silicone rubber material is modeled based on the absolute nodal coordinate formulation plate element,and this model is used to calculate the deformation of a silicone rubber finger.Based on the theory of the conventional flat plate element of the absolute nodal coordinate formulation,the ANCF curved plate theory is verified,and the calculation example is divided into different elements for calculation,and the characteristic of rapid convergence of the ANCF curved plate element is obtained.Under the ANCF curved plate element,a length constraint method is implemented.The Hookean model and Yeoh model are selected to describe the stress-strain relationship of the silicone rubber material,the original constitutive model is improved,and the stiffness matrix of the Hookean model and Yeoh model based on the absolute node coordinate formulation is derived.The selective reduced integration is used to solve the problem of volume locking,and the elimination of volume lock is verified through comparative simulation.Experiments have been conducted to verify the correctness of the improved Yeoh model based on the absolute node coordinate method.The difference between the Hookean model and the Yeoh model is analyzed through a comparative simulation.The Yeoh model based on the absolute nodal coordinate formulation is used to calculate a pneumatic soft finger,and the deformation of a single joint and two joints is analyzed.Compared the results from ABAQUS,it can be concluded that the hyperelastic model based on the absolute node coordinate formulation can effectively calculate the deformation of such structures.