Modelling the spindle–holder taper joint in machine tools: A tapered zero-thickness finite element method

• A tapered zero-thickness finite element method is proposed to model the taper joint.
• The coupling of adjacent degrees of freedom of the taper joint is considered.
• The axial, radial and tangential effects of the taper joint are considered.
• A combined analytical–experimental parameter identification method is presented.
• A specimen that the six rigid-body modes can easily be acquired is presented.

This study presents a tapered zero-thickness finite element model together with its parameter identification method for modelling the spindle–holder taper joint in machine tools. In the presented model, the spindle and the holder are modelled as solid elements and the taper joint is modelled as a tapered zero-thickness finite element with stiffness and damping but without mass or thickness. The proposed model considers not only the coupling of adjacent degrees of freedom but also the radial, tangential and axial effects of the spindle–holder taper joint. Based on the inverse relationship between the dynamic matrix and frequency response function matrix of a multi-degree-of-freedom system, this study proposes a combined analytical–experimental method to identify the stiffness matrix and damping coefficient of the proposed tapered zero-thickness finite element. The method extracts those parameters from FRFs of an entire specimen that contains only the spindle–holder taper joint. The simulated FRF obtained from the proposed model matches the experimental FRF quite well, which indicates that the presented method provides high accuracy and is easy to implement in modelling the spindle–holder taper joint.