Modelling and manufacturing of a dragonfly wing as basis for bionic research

Working principles in nature have been optimised by evolution for millions of years. Today we try to understand how these principles work and how they could be used in technical applications. Prominent examples for solutions which are inspired by bionic research are the Velcro fastener (inspired by the plant \u27Arcticum lappa\u27) [Pahl et al., 2003], swim suits (inspired by shark skin) [Thilmany, 2004] and self-cleaning surfaces using the lotus effect [von Baeyer, 2000]. The topic of aerodynamics is another large area for research and innovation in which we still hope to be able to learn from nature. The dragonfly combines very light wing structures with amazing flying abilities [Okamoto, 1996]. In order to study the exact properties of the dragonfly wing and to understand how this properties can be achieved, it is necessary to reproduce the geometry of the wing at a larger scale. This large scale model can be used to conduct further aerodynamic tests in a wind tunnel. The results of such investigations can lead to new impulses for the development of aircraft and micro air vehicles. In this paper the authors will describe the modelling and building of an enlarged model of a dragonfly wing as base for further bionic research

A matrix representation of the CPM/PDD approach as a means for change impact analysis

Engineering changes occur in every life cycle phase of a product and in every step of the product development process. Today, the importance of engineering change management as a part of product development is constantly rising. Reasons besides the globalisation are that customers are interested in more customised products at the price of a mass product - a phenomenon [Eckert et al. 2003] call mass customisation -, failures in design and changes in customer wishes that can not entirely be prevented. According to Lindemann and Reichwald [Lindemann et. al. 1998] engineering change management consumes 30 to 50 %, sometimes even up to 70 % of the capacity in product development. According to Wildemann [Wildemann 2006] the average cost of one engineering change is about 1.400 EUR (working hours, scrapping and tooling cost, but no organisational cost). Multiplied with 425 changes per month in average, identified by Deubzer et. al. [Deubzer 2005], that results in 7.1 million EUR change cost per year for an average company in the automobile manufacturing industry. According to the rule of ten [VDI2247], engineering changes become more expensive and time consuming the later they occur in the product life. Hence, it is advantageous to perform changes as early as possible [Lindemann et al. 1998]. But on the other hand, today\u27;s markets and customer wishes change so quickly that a frontloading of engineering changes hinders the technological development of a company and endangers competitive advantages through innovation and customisation. Additionally, again according to Lindemann and Reichwald [Lindemann et. al. 1998], about 40 % of changes are recognised only after the completion of the production tools. That is supported by Wildemann [Wildemann 2006] who states that 50 % of the design-related changes happen in the preseries and series phase of the product development process. Approaches like Design for Changeability help to reduce change cost but even can not foresee all possible changes. Therefore, (engineering) change management is still an important task in product development. Thereof, especially the area of change impact analysis is the most significant part

Innovative lightweight aircraft design : a student competition

Education in engineering design is a challenging task. On the one hand the students have to get a broad theoretical basis and engineering expertise, on the other hand they have to learn how to apply their knowledge and how to face real technical problems [Pulko, 2004]. Since time in University is limited (in Germany a engineering degree at university level takes about 5 years to complete) often an emphasis is put on a sound theoretical education at the expense of practical experience. This paper presents a student competition between four German universities, which provides a practical team-work project for engineering (design) students that nearly spans the whole life-cycle from brainstorming for product ideas to manufacturing and usage of the product. The development task is an aircraft or flight device totally made of steel. Aim of the project is to apply the theoretical knowledge at a practical task

Change impact and risk analysis (CIRA) : combining the CPM/PDD theory and FMEA-methodology for an improved engineering change management

The change process is one of the most critical tasks of the product development process. Misinterpretation or lack of knowledge about impacts or risks of changes can cause serious disadvantages to companies, e.g. high failure or change costs or image losses caused by products with a quality that is unacceptable. Supervising the change process is a challenging task; an important part of this task is the analysis and assessment of risks and impacts of changes. This contribution presents an approach to support the process of analysing and assessing the effects of changes in the product development process. The approach is based on two methods: First on the CPM/PDD theory developed at the Institute of Engineering Design/CAD in order to synthesise potential solutions to change requests and to ana-lyse their impacts; second on the common Failure Modes and Effects Analysis (FMEA)-method in order to assess the risks and impacts of changes and to document the analysis

Comparison of knowledge representation in PDM and by semantic networks

\u27Nowadays, computer-aided tools have enabled the creation of electronic design documents on an unprecedented scale, while determining and finding what can be reused for a new design is like searching for a \u27needle in a haystack\u27. (…) The availability of such extensive knowledge resources is creating new challenges as well as opportunities for research on how to retrieve and reuse the knowl-edge from existing designs.\u27 [1] If the requested knowledge is implicit (which means that it is only in the minds of the employees of a company) the retrieval and reuse of knowledge is even more com-plicated. By representing the (engineering) data backbone of a company, PDM systems are the software implementation which should support the designer to retrieve information about existing and successful design projects. This paper shows that the known data classification approaches of common PDM systems are not applicable to represent implicit (tacit) knowledge. Furthermore a new approach to knowledge representation is introduced by using Semantic Networks. The feasibility of the presented work is shown by a use-case scenario in which the conventional PDM system supported product development process is compared with the proposed way by using the soft-ware \u27The Semaril\u27 — a software tool developed at the Institute of Engineering Design/CAD based on Semantic Networks [2]

Classification of tools and methods for knowledge management in product development

"Der Fortschritt lebt vom Austausch des Wissens" (Progress is based on the exchange of knowledge - Albert Einstein), is only one of many famous sayings that underline the importance of knowledge. [Vajna et. al. 2001] quote a statement from 1907 saying that besides dedicated employees the application of knowledge had already been one of the most decisive factors of success for companies that time. This is more applied to our, by globalization characterised, time. A neglect of existing potentials of the employees\u27 knowledge has negative impacts on product development [Krause et. al. 2007]. That is why the missing accessibility of personal knowledge to the company and its employees leads to wasting in the company in the form of redundant developments or dissimilar decisions [Probst et. al. 2006]. Only a structured and systematic management of knowledge resources enables a company to benefit from yet unused personal knowledge [Krause et. al. 2007] and, thus, to positively influence the main targets cost, time and quality [Klabunde 2003]. Recently, a huge number of innovative knowledge management methods and tools have been developed, but only few of them have been applied. Problems that hinder the application of those methods and tools have been discussed by [Klabunde 2003]. Among these is also the limited usage of the tools due to missing knowledge about the usage. The aim of this paper is to combine knowledge management tools and methods with product development. The method to do this is to consider the knowledge management blocks according to Probst [Probst et.al. 2006], deriving from the area of business administration, in the context of the product development process according to VDI 2221 [VDI 1993]. Based on this consideration, the goal of this contribution is to identify and propose existing solutions for knowledge management in the different phases of product development

Modelling and manufacturing of a dragonfly wing as basis for bionic research

Working principles in nature have been optimised by evolution for millions of years. Today we try to understand how these principles work and how they could be used in technical applications. Prominent examples for solutions which are inspired by bionic research are the Velcro fastener (inspired by the plant 'Arcticum lappa') [Pahl et al., 2003], swim suits (inspired by shark skin) [Thilmany, 2004] and self-cleaning surfaces using the lotus effect [von Baeyer, 2000]. The topic of aerodynamics is another large area for research and innovation in which we still hope to be able to learn from nature. The dragonfly combines very light wing structures with amazing flying abilities [Okamoto, 1996]. In order to study the exact properties of the dragonfly wing and to understand how this properties can be achieved, it is necessary to reproduce the geometry of the wing at a larger scale. This large scale model can be used to conduct further aerodynamic tests in a wind tunnel. The results of such investigations can lead to new impulses for the development of aircraft and micro air vehicles. In this paper the authors will describe the modelling and building of an enlarged model of a dragonfly wing as base for further bionic research

What is design knowledge from the viewpoint of CPM/PDD?

Knowledge is a very common term in engineering design and also extensively discussed. There are many theories describing what knowledge is and how it should be managed in engineering design. But no shown/presented concept or definition is generally accepted. One reason for this are differing theories and views about the underlying development/design process. Therefore, it is necessary to find an adequate model for knowledge, which considers the product development process. This paper is based on the Characteristics-Properties Modelling / Property-Driven Development (CPM/PDD) approach [Weber 2005]. The product model (i.e. CPM) and the model of the product development process (i.e. PDD) are based on the clear distinction between characteristics and properties and, thus, enable a structured and integrated consideration of design knowledge. On this account, this paper provides a closer look on design knowledge in the context of CPM/PDD. Among other considerations, a method out of the theoretical computer science is applied to this context

Change impact and risk analysis (CIRA) : combining the CPM/PDD theory and FMEA-methodology for an improved engineering change management

The change process is one of the most critical tasks of the product development process. Misinterpretation or lack of knowledge about impacts or risks of changes can cause serious disadvantages to companies, e.g. high failure or change costs or image losses caused by products with a quality that is unacceptable. Supervising the change process is a challenging task; an important part of this task is the analysis and assessment of risks and impacts of changes. This contribution presents an approach to support the process of analysing and assessing the effects of changes in the product development process. The approach is based on two methods: First on the CPM/PDD theory developed at the Institute of Engineering Design/CAD in order to synthesise potential solutions to change requests and to ana-lyse their impacts; second on the common Failure Modes and Effects Analysis (FMEA)-method in order to assess the risks and impacts of changes and to document the analysis

New concepts to manage and provide solutions during the product development process : CPM/PDD solutions patterns as basis for a behaviour describing catalogue

Die vorliegende Arbeit stellt einen elektronischen Konstruktionskatalog auf Basis des Characteristics-Properties Modelling (CPM) bzw. Property-driven Development (PDD) vor, der den Produktentwickler in erster Linie bei der Suche nach Lösungsmustern und damit nach realisierten Lösungen unterstützen soll. Der signifikante Unterschied zu bereits existierenden Konstruktionskatalogsystemen, die sich lediglich auf die Abbildung von Merkmalen, also z.B. Geometrie, Werkstoffe usw., beschränken, ist die Möglichkeit, nach Eigenschaften und damit Produktverhaltensaspekten und deren Ausprägungen zu suchen. Speziell in frühen Konstruktionsphasen, in denen der Produktentwickler an der Funktionserfüllung oder anderen Eigenschaften eines Zulieferteils interessiert ist, unterstützen ihn aktuelle Katalogsysteme nicht, da in ihnen nur Geometrie abgebildet ist. Zu Beginn dieser Arbeit werden die relevanten Grundlagen wie die entsprechende Begriffswelt, Methoden der prinzipiellen Lösungssuche, Grundlagen für Katalogsysteme und existierende Klassifizierungsansätze zusammengefasst. Weiterführend erfolgt eine Beschreibung der Defizite und Diskussion existierender Katalogsysteme sowie die Darstellung eines Ansatzes für ein verhaltensbeschreibendes Katalogsystem, das die Vorteile existierender Ansätze integriert und das durch die Eigenschaftssuche erweitert wird. Im Anschluss wird die darauf aufbauende prototypische Implementierung vorgestellt und anhand eines Versuchsaufbaus gezeigt, wie sich der Nutzen eines solchen Konstruktionskatalogs für den Produktentwickler empirisch beweisen lässt.This doctorial thesis introduces an electronic engineering design catalogue based on Characteristics-Properties Modelling (CPM) and Property-Driven Development (PDD) which supports the engineering designer in searching for solution patterns and realized solutions. Existing catalogue systems are limited to representing product characteristics (e.g. geometry or material) and therefore provide no support in the early phases of product development, in which the product developer focuses on properties such as functionality or other aspects of product behaviour. The catalogue introduced in this dissertation addresses this significant shortcoming by integrating an option of searching for properties, which, in turn, allows the designer to search for product behaviour. At the beginning of the dissertation the "state of the art\u27; is described (basic definitions, methods of searching for principal solutions, basic principles of catalogue systems and established classification approaches). After showing and discussing deficits of existing catalogue systems this thesis presents an approach towards a catalogue system which includes the benefits of existing systems and integrates the option of searching for properties. Finally a prototypical software implementation of the introduced approach and an experimental set-up for proving its benefits are shown