The Analysis of Soft Elastohydrodynamic Lubrication with Pure Squeeze Motion on Hyperelastic Materials

Abstract

With the advancement of medical technology technologies such as AI-assisted surgery and surgical simulation have developed rapidly The relationship between force and displacement of the surgical procedure is especially important for the tactile and visual aspects of surgical applications In this study FEM is used to establish a transient squeeze soft-EHL system The Reynolds equation coupled hyperelastic material model and the load balance equation were used to investigate different hyperelastic parameters thickness and load conditions by giving a constant load to a rigid ball which squeezes finite thickness of the hyperelastic flats Considering the fluid can withstand the load using this model as an indentation simulator discuss the effect of fluid on force and displacement The gray matter and white matter of brain tissue which is extremely soft and requires a small load during surgery are selected as our studying objects The simulation results reveal that the assumptions of the EHL model should be corrected if soft material produced large deformation The difference between the force and the displacement of the dry contact of hyperelastic model and soft-EHL increases as the load increases The softer gray matter has a larger deformation than the white matter and the difference in deformation between the two increases with thickness When the amount of deformation is fixed it can be found that as the thickness increases the load required for the white matter is larger than that of the gray matter

Date of Award	2019
Original language	English
Supervisor	Wang-Long Li (Supervisor)