This thesis focuses on advancing the understanding of the dynamic behaviour for double-sided components by addressing the effects of workholding configurations. The research targets key questions regarding workpiece dynamics in order to enable this type of machining approach.
The study begins by reviewing the relevant state-of-the-art literature on machining induced vibrations, concentrating on chatter prediction models, as well as chatter avoidance in flexible parts. Complemented by the evaluation of research targeting machining fixture layout optimisation, a potential gap in knowledge is highlighted and aimed as a research avenue for this project.
The theoretical background is then summarised, describing the mathematical basis of modal analysis, finite element modelling, experimental modal analysis, and model updating methods. This foundation serves to underpin the framework and procedures for the subsequent chapters.
Optimisation programming and software integration follows, explaining the steps involved in creating an automated link between numerical software platforms for Finite Element Analysis (FEA) and a Particle Swarm Optimisation approaches. This integration creates a robust platform for evaluating and enhancing double-sided access and minimally held fixturing layouts.
The thesis then explores how validation and updating procedures enhance the predictive behaviour of FEA models, and the preferred experimental approaches required for model validation. This is achieved by several modal testing activities of components and structures, which provide the physical data to validate the models.
With a connection established between machining stability and computer-aided fixture design optimisation routines, an FEA-based methodology is employed to derive optimal solutions for external workholding layouts. The optimisation method is then expanded onto the finishing stages of a component, specifically targeting parting-off tab layouts. This extension aims to improve the definition of breakaway tab arrangements through the investigation of suitable modelling approaches and optimisation routines.
The significance of this study lies in its potential industrial impact, enabling novel machining approaches for double-sided components in minimally held environments. The developed optimisation routines have the capability to target design areas traditionally managed manually based on experience. Additionally, enhanced FEA modelling techniques contribute to the refinement and precision of workholding evaluations.
In conclusion, this thesis offers a comprehensive framework for the definition and optimisation of workholding layouts in double-sided machining. By addressing critical questions in machining dynamics, it advances the industrial application of these techniques, contributing to the ongoing evolution of machining methodologies.
