Making correct design decisions during the early stages of the engineering design process is increasingly seen to be important, as changes during the later stage can be costly. Life Cycle Assessment (LCA) is used as a method to evaluate the design from 'cradle to grave'. In concept design, decisions are made that have a most significant influence on the life cycle, but at this stage the lack of detail makes LCA very difficult if not impossible. This thesis introduces a method that enables an 'order-of-magnitude' life cycle assessment during the concept stage of the design process. This is achieved by modelling the life cycle inventory as a function of design parameters for complete product families used in engineering design. The hypothesis is that relatively few so-called life cycle parameters determine the largest part of the life cycle inventory. Furthermore, design parameters are related to life cycle parameters, which are mathematically modelled. Design parameters are chosen so that they can be estimated early during the design process. The models of the life cycle parameters are expressed in terms of upper and lower limits, summarising data from many product families. More detailed models describe the relationships of single product families. The method is suitable for software implementation, which will especially aid the handling of sensitivity analysis. Two case studies (sealed lead acid batteries, three-phase asynchronous motors) are used to illustrate how the life cycle parameters are related to the design parameters. An overall outline of how the method is implemented into the overall design process completes the thesis (evaluation of parallel and series configuration hybrid electric vehicle).

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The work reported here reflects the fundamental research undertaken by the author into the technologies of Rapid Prototyping, Rapid Manufacturing and Rapid Tooling. This research was undertaken over 4 years, in a period when these technologies were experiencing huge change, through innovation and development, to produce viable and reliable industrial processes. The research presented here deals with the two low cost, high speed Rapid Prototyping manufacturing processes. The first technology produces concept models for verifying design intent in the early stages of the product development cycle — referred to as the Z-Corps 3D Printing, 3DP process. The second technology investigated was the EnvisionTec 3D Digital Light Manufacturing, DLM process. This is machine capable of producing final parts in real engineering materials. In both cases the default manufacturing settings and materials were evaluated for accuracy, finish and material properties and an experimental test methodology was developed. Each process was then optimised utilising Taguchi techniques and applied to industrial projects. Finite Element Analysis (FEA), has been used to predict best build orientation for these non-isotropic materials. This work investigating the Z-Corps 3D printing process has improved the accuracy by 2%, part strength by 25% using new infiltrates and has been applied to both production of polymer injection mould tool inserts and electrode manufacture. The EnvisionTec Digital Light Manufacturing build parameters have been optimised and characterised for accuracy, hardness, part strength, surface finish. The application of FEA analysis using Non-isotropic properties has been shown to improve product performance by 14% and the optimised process has been applied to Rapid Tooling applications. In all twelve case studies are presented here, several of which have been turned into successful commercial products, and for one case over 1 million products have been sold.

It is widely accepted that design changes, occurring during construction projects, can account for a significant proportion of the engineering design consultant’s total cost. Projects with multidisciplinary, distributed and virtual project teams, working on technically challenging problems, make the impact of design changes increasingly difficult to predict. Existing guidance suggests ‘best practice’ protocols for recording, reporting and communicating design changes. However, best practice protocols do not provide guidance for predicting the impact in terms of project cost and duration. Impact assessments are essential in the decision to implement changes and subsequently being in a position to justify fee claims to clients. Decisions in the construction process are normally based on experience and professional knowledge of practitioners, such as architects, engineers, project managers and contractors. There is evidence, however, that, in design management, sharing of professional knowledge tends to be tacit and socially constructed (where team members draw on their own experience and the experience of those around them). Although practitioner experience and intuition is invaluable in determining the impact of a design change, this research is based on the position that a more structured process is required. It is argued that a software based approach, to better inform practitioners’ existing knowledge, is required to improve the quality and accuracy of impact assessments. The current practice for managing and assessing change was examined through studying the operations of the case study organisation, undertaking a literature review and conducting interviews with representatives from organisations in other industries. A new project management tool was then developed which provides support for practitioners to make better-informed impact assessments. This is achieved through providing: (a) a process map to visualise rework, (b) instant access to previous similar impact assessments and (c) an embedded, standardised method for knowledge sharing. The concept for this tool was developed by combining appropriate techniques and tools found in the design management and knowledge management literature. Users are further encouraged to use the software tool through a system to automate the updating of Microsoft Project schedules, thus eliminating time currently spent scheduling rework. The validation and verification stages consisted of formal interviews with potential users and preliminary user testing. Regular feedback on the support tool was obtained from a wide range of peers and potential users and this was then used to develop its functionality. Positive feedback has included comments about the concept of the tool, user-friendliness and need for implementation.

Engineers Talk Be it through conversations, meetings, informal discussion, phone calls or E-Mail, Engineering Design Communication is the main tributary for the sharing of knowledge, thoughts and ideas, and therefore, fundamental to Engineering Work. An engineer spends a significant portion of their day communicating as they 'fill in the gaps' left by formal documentation and processes. It is thereby, an inherent source of explicit design rationale that relates to (and very often supplements) Engineering Records and their generation. Engineering Design Communication is not only central for Engineering Work and Records but also offers potential - through aggregation - to reveal underlying features, patterns and signatures that could aid current and future Engineering Project Management. As Engineering Design Communication plays such a pivotal role, it comes as no surprise that there is much extant research. The majority of this is descriptive and has focused on identifying patterns in engineers' communication behaviour as well as analysing the utility of currently employed communication tools/mediums (such as, E-Mail and meetings). However, little prescriptive research - through either a tool or process - has been undertaken. This may be due to the considerable challenges facing research in this field such as the need to maintain a high-level of Engineering Context, ensure the right engineers are able to participate and associate the communication with its respective Engineering Records. All of which, has to be achieved within an Engineering Context where teams are becoming larger, more mobile, multi-disciplinary & distributed, and often performing variant or incremental design. Although, it is argued that Social Media has the potential to militate these challenges through the use of technologies that provide agile development, support for ubiquitous computing and sharing of multimedia. Therefore, this thesis investigates how Social Media can be used to support Engineering Design Communication. This is achieved through the elicitation and synthesis of the requirements for supporting Engineering Design Communication, and consideration of the effective application of the Social Media. This forms the basis from which a Social Media approach to support Engineering Design Communication is created and then instantiated within a tool called PartBook. PartBook has been developed iteratively and involved an industrial study to evaluate and improve functionality. It has since been used within an eleven week Formula Student project involving thirty-four students from multiple engineering disciplines in a distributed working environment. The analysis of which addresses the validation of the requirements that has led to amendments and generation of new requirements as well as evaluation of the Social Media approach that has led to insights into the potential impact such a tool could bring to Engineering Work, Records and Project Management.

In der vorliegenden Habilitationsschrift werden im ersten Teil bekannte aber auch ausgewählte neue Verfahren zum Fügen von Metallen mit Kunststoffen vorgestellt und miteinander verglichen. Im zweiten Teil werden verschiedene Berechnungsmöglichkeiten für die Auslegung bzw. die Nachweisführung von mechanisch gefügten Verbindungen vorgestellt. Hierbei handelt es sich ebenfalls um bekannte Konzepte als auch um neue Konzepte aus eigenen Forschungsvorhaben. Anhand der Aufbereitung dieser Konzepte in Algorithmen nach DIN 66001 und der Bereitstellung von Beispielen, welche sich auf die Algorithmen beziehen, sind diese einfach anwendbar und für die studentische Ausbildung gut geeignet.:1 Bekannte und neue Fügeverfahren im Leichtbau 1.1 Einleitung zum ersten Kapitel 1.2 Clinchen 1.3 Ultrasonic Fusion Bonding and Clinching 1.4 Clinching with a lost Ring 1.5 Blindnieten 1.6 Flow Drilling Riveting 1.7 Zusammenfassung 2 Auslegungsmöglichkeiten und Bemessungskonzepte 2.1 Einleitung zum zweiten Kapitel 2.2 Berechnung von Vollnietverbindungen nach DIN EN 1993-1-8 2.3 Berechnung von Blindnietverbindungen nach J. Grandt 2.4 Berechnung von Clinch-, Stanzniet- und Blindnietverbindungen nach der Grenznahtfestigkeit / In the first part of this habilitation thesis, known but also selected new processes for joining metals with plastics presented and compared. In the second part, various calculation options for the design and verification of mechanically joined connections are presented. These are also well-known concepts as well as new concepts from our own research projects. Based on the processing of these concepts in algorithms according to DIN 66001 and the provision of examples that refer to the algorithms, they are easy to use and well suited for student training.:1 Bekannte und neue Fügeverfahren im Leichtbau 1.1 Einleitung zum ersten Kapitel 1.2 Clinchen 1.3 Ultrasonic Fusion Bonding and Clinching 1.4 Clinching with a lost Ring 1.5 Blindnieten 1.6 Flow Drilling Riveting 1.7 Zusammenfassung 2 Auslegungsmöglichkeiten und Bemessungskonzepte 2.1 Einleitung zum zweiten Kapitel 2.2 Berechnung von Vollnietverbindungen nach DIN EN 1993-1-8 2.3 Berechnung von Blindnietverbindungen nach J. Grandt 2.4 Berechnung von Clinch-, Stanzniet- und Blindnietverbindungen nach der Grenznahtfestigkeit

Optimisation is one of the most important and challenging part of any engineering design. In real world design problems one faces multiobjective optimisation under constraints. The optimal solution in these cases is not unique because the objectives can contradict each other. In such cases, a set of optimal solutions which forms a Pareto frontier in the objective space is considered. There are many algorithms to generate the Pareto frontier. However, only a few of them are potentially capable of providing an evenly distributed set of the solutions. Such a property is especially important in real-life design because a decision maker is usually able to analyse only a very limited quantity of solutions. This thesis consists of two main parts. At first, it develops and gives the detailed description of two different algorithms that are able to generate an evenly distributed Pareto set in a general formulation. One is a classical approach and called Directed Search Domain (DSD) and the other, the cylindrical constraint evolutionary algorithm (CCEA), is a hybrid population based method. The efficiency of the algorithms are demonstrated by a number of challenging test cases and the comparisons with the results of the other existing methods. It is shown that the proposed methods are successful in generating the Pareto solutions even when some existing methods fail. In real world design problems, deterministic approaches cannot provide a reliable solution as in the event of uncertainty, deterministic optimal solution would be infeasible in many instances. Therefore a solution less sensitive to problem perturbation is desirable. This leads to the robust solution which is the focus of the second part of the thesis. In the literature, there are some techniques tailored for robust optimisation. However, most of them are either computationally expensive or do not systematically articulate the designer preferences into a robust solution. In this thesis, by introducing a measure for robustness in multiobjective context, a tunable robust function (TRF) is presented. Including the TRF in the problem formulation, it is demonstrated that the desirable robust solution based on designer preferences can be obtained. This not only provides the robust solution but also gives a control over the robustness level. The method is efficient as it only increases the dimension of the problem by one irrespective of the dimension of the original problem.