A Framework for Virtualising the Manufacture of Formed Components to Support Design

Abstract

This thesis reports participant based action research undertaken in a medium sized industrial sponsor company in which a Finite Element Analysis (FEA) based ‘Virtual Manufacturing’ (VM) system was created to support the design of precision spring fastener components volume-produced in multi-stage metal forming processes. The system was then implemented and tested in the design process of the industrial sponsor to gauge its efficacy in improving design success. This activity has resulted in two key contributions to knowledge described in this thesis: - The stages, techniques, issues and feasibility of virtualising the manufacturing, testing and evaluation process of formed mechanical components using multi-stage manufacturing process simulation to support design.- A framework for design support using manufacturing process simulation which provides a holistic view of the key aspects to consider in a three-stage process of virtualisation, automation and distributable tool development.These contributions address a gap in literature identified through a review of primarily sheet metal forming literature for which automated FEA simulation has been widely implemented in a process-orientated approach to evaluating and improving part feasibility, manufacturability and process capability of parts and their processes. There are few examples of automated FEA systems being developed in a product design orientated approach of producing accurate virtual prototypes which are packaged up to be used in further use-case models to evaluate design performance. This requires a different methodology to integrate the manufacturing stages and testing appropriately.Design and manufacturing companies need to cut costs, improve performance and reduce product development cycles to stay competitive in the globalized world. This requirement applies to manufacturers of all scales from large corporations through to Small and Medium Sized Enterprises (SMEs). While they may face the challenges in different ways, and from different positions, all sizes of manufacturing company can benefit from the adoption of Computer Aided Engineering (CAE). CAE technology encompasses a vast and diverse field of activities but in mechanical design it is dominated by Computer Aided Design (CAD) systems and advanced simulation and analysis systems such as Finite Element Analysis (FEA).Many companies have adopted or are in the process of adopting FEA for use in their design processes but the ability to gain a competitive advantage by merely having specialist analysts supporting design projects is passing. FEA has become much more ubiquitous in industry so competitive advantages must now come from better practice with existing tools or new analysis technologies. This has led to companies seeking automation, integrated design environments and better knowledge management.The Sheet Metal Forming (SMF) industry is no different. SMF is a widely used method of manufacturing components from sheet metal into products for many different applications and scales. Examples include small electrical fittings, automotive body panels and large aircraft structures. The parts can be designed for aesthetic and/or mechanical uses which put different requirements and constraints on the design and manufacturing processes.For manufacturers of products made in SMF processes; the need for FEA is very important. However the use of FEA for SMF almost solely focuses on how the parts are made. This includes part feasibility, manufacturability and process capability. Rarely has it been reported where FEA is used to simulate a (multi-stage) forming process to output a virtual part with an accurate geometric form which has been found to be impractical to attain directly with parametric CAD.By simulating the manufacturing process, both design parameters (for the blank and the tooling) and process parameters can be adjusted to produce virtualised samples (or prototypes) which represent a prediction of the manufacturing output for each configuration along with the material state resulting from the process. These representations can then be tested in further analyses to predict their mechanical behaviour in certain conditions which makes it useful as a design tool.This capability can be achieved by taking an integrated approach to bringing together FEA models of the manufacturing process and a software framework to produce ‘Virtual Prototypes’ (VPTs) which are then imported and tested in further FEA performance testing models.The implementation of this type of system in the design process of a manufacturer of specialist spring fasteners has been shown to reduce the number of design iterations, increase project success and improve the companies’ reputation with customers. However it has also revealed a large number of limitations which, to make the approach feasible, must be handled carefully.

Date of Award	27 Jun 2017
Original language	English
Awarding Institution	University of Bath
Supervisor	Patrick Keogh (Supervisor) & Ben Hicks (Supervisor)