Dynamic model and machining mechanism of wire sawing

During the wire sawing process, the wire usually undergoes large deformation, which leads to changes in the sawing force and the contact state between wire and workpiece, and in turn affects the material removal rate (MRR) and the workpiece quality. This paper presents a general dynamic model for the wire sawing. The model aims to describe the coupling relations among the contact state of wire and workpiece, the sawing force and the material removal. An iterative simulation flow was designed by the proposed model. The experiment of wire sawing with rocking and reciprocating (WSRR) was carried out to validate the proposed model. The comparison results indicated that the proposed model replicated the entire sawing experiment well. On this basis, the influences of wire speed, feed rate, rocking angle, preload force, guide rollers distance and workpiece size on sawing force, contact length and MRR were systematically analyzed. The results show that the wire reciprocating is the root cause of saw marks. Workpiece rocking causes the wire bow angle to change periodically and significantly reduces the contact length. Wire speed and feed rate has great influence on the value of normal force. The force fluctuation is affected by the maximum rocking angle and wire preloading force. MRR is mainly determined by the feed speed. The feed rate, maximum wire speed, maximum rocking angle, and preloading force could influence on the fluctuation range of the MRR. This work provides a general model for a better understanding of the wire sawing.