Shrink fit tool holder connection stiffness/damping modeling for frequency response prediction in milling

In this paper we present a finite element modeling approach to determine the stiffness and damping behavior between the tool and holder in thermal shrink fit connections. The continuous contact stiffness/damping profile between the holder and portion of the tool inside the holder is approximated by defining coordinates along the interface contact length and assigning position-dependent stiffness and equivalent viscous damping values between the tool and holder. These values are incorporated into the third generation receptance coupling substructure analysis (RCSA) method, which is used to predict the tool point frequency response for milling applications. Once the holder and inserted tool section are connected using the finite element analysis-based stiffness and damping values, this subassembly is then rigidly coupled to the (measured) spindle–holder base and (modeled) tool. Experimental validation is provided.