In-Process Monitoring and Analysis of Dynamic Disturbances in Boring and Trepanning Association (Bta) Deep Drilling

Abstract

This paper presents an approach to monitor the dynamic disturbances of a BTA (boring and trepanning association) deep drilling system. High length to diameter ratios are the key characteristic of deep drilling processes compared to conventional drilling applications. Since length to diameter ratios of up to 150 for slender tool-boring-bar assemblies are common, the deep drilling process is sensitive to dynamic disturbances such as chatter and whirling vibrations. Whirling vibrations usually effect the shape of the hole and cause holes with several lobes. To gain a deeper understanding of the dynamic state of the process, a sensor application has been developed and was tested in practice. Experimental investigations on BTA deep drilling with continuous multi-sensory monitoring were conducted. The used setup allowed the determination of the frequencies of chatter and whirling vibrations during the cutting process by analysing the logged data using a continuous short-time Fourier transformation (STFT).

The Chaotic Property of BTA Deep-Hole Machining System under the Effect of Inner Cutting Fluid

“…On this basis, Messaoud et al [24][25][26] further proposed an online futter monitoring strategy based on control chart through dynamic modeling of the nonlinear time series of the deep-hole machining system, and investigated the infuence of the position of the adjusted guide block and drilling depth on the system chatter. Steininger and Bleicher [27] adopted a continuous multidimensional sensor system to monitor the dynamic disturbance of diferent parameter changes on the deep-hole machining system, and adjusted the parameter changes to deal with the system futter and rotary vibration, which proved that variable speed cutting plays a role in improving the system stability. Te actual production system for BTA deep hole machining involves the rotation of the boring bar, which is accompanied by the infow and outfow of cutting fuid.…”

Surface integrity of machined surface in simultaneous cutting of CFRP

“…Many studies have been conducted on general metal drilling until now, and methods for drilling relatively shallow holes are almost established. In recent years, research has been conducted on monitoring technology for machining deep holes with high precision [1,2]. Furthermore, many researchers have been studying on the drilling of difficult-toprocess materials [3,4].…”