Exploring the influence of friction in the puncture mechanics of soft solids

Friction is an ever-present force in our lives, affecting the interaction between objects in numerous ways. The common hypothesis of frictionless contact between a foreign rigid object (needle) and a target material during puncturing leads to a constant penetration force. However, experimental observations reveal a linear increase in penetration force as the needle tip delves deeper. This force increment arises from the interplay of friction and adhesion at needle-solid interface. The present work provides an insight into the measure of friction and adhesion quasi-static characteristics at the needle-solid interface through puncture experiments. To this end, an axisymmetric hyperelastic model is presented to describe the expansion of a cavity under the contact pressure of the penetrating needle. In addition, the competing mechanisms of cavity expansion and mode I cracking during needle penetration in a soft solid are discussed.