A multi-physics-based approach to design of the smart cutting tool and its implementation and application perspectives

Abstract

This thesis presents a multi-physics-based approach to the design and analysis of smart cutting tools for emerging industrial requirements, within an innovative design process. The design process is in stages according to design specifications and requires analysis, conceptual design, detailed design, prototype production and service testing. The research presented in the thesis follows the design process but focuses on the detailed design of the smart turning tool, including mechanical design, electrical wiring and sensor circuitry, embedded algorithms development, and multi-physics-based simulation for the tool system integration, design analysis and optimisation. The thesis includes the introduction of the research background, a critical literature review of the research topic, a multi-physics-based design and analysis of the smart cutting tool, a mechanical structural detail design of the prototype smart turning tool, the electrical system design focusing on cutting force measurement and embedded wireless communication features, and the final experimental testing and calibration of the smart cutting tool. The contributions to knowledge are highlighted in the conclusions chapter towards the end of the thesis. The research proposes multi-physics-based design and analysis concepts for a smart turning tool, which can measure the cutting forces on a 0.1 N scale and can also be used to monitor the tool condition, particularly for ultraprecision and micro-machining purposes. The smart turning tool is a sensored tool, constructed with wireless and plug-and-produce features. The tool design modelling and simulation was undertaken within a multi-physics modelling and analysis environment-based on COMSOL. This integrates the piezoelectric physics with mechanical structural design and radio frequency electronic communications of cutting force signals. The multi-physics simulation method takes account of all design-mechanics-physics-electronics analysis and transformations simultaneously within one computational environment, including FEA analysis, modal analysis, structural deformation, lead piezoelectric effect and wireless data/signal simulation. With the multi-physics simulation developed, the integrated design of the smart turning tool and its performance can be physically analysed and optimised in a virtual environment. The tool design process follows the total design methodology, which can be strictly executed in several design stages. Both mechanical and electrical design of the smart cutting tool are embodied into the tool detail design. The tool mechanical structure is systematically built from the selection of the tool material, through the structure analysis and further progressed with static force – strain/stress transformation, equivalent force measurement and calibration. The electrical circuitry was systematically developed from developing the customised charge amplifier, detail design of the main circuitry and coding development procedure, preliminary PCB fabrication and multi-sensor port PCB development, as well as the real-time cutting force monitoring programming and interface coding. The experiment calibrations and cutting trials with the tool system are also designed in light of the total design methodology. The experiment procedure for using the smart turning tool is further presented in two different sections. The thesis concludes with a further discussion on the main research findings, which are further supported by the highlighted contributions to knowledge and recommendations for future work.