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Item type:Publication, Access status: with files , Eine Methode zur Bewertung von Anlaufrisiken in der Produktentwicklung für die FlugzeugindustrieIn this thesis a methodical support for early identification and minimization of ramp-up risks with the help of response strategies is developed. Therefore the approach is divided into two main phases and focusing on the support of the product development until the transition to production. Within the first phase the identification of potential risk areas will be conducted based on a new impact model. During the second main phase the identified areas will be analyzed within a detailed risk analysis. Basis for the analysis is a Monte-Carlo-Simulation. The response strategies for reduction of ramp-up risks are derived from a generic measures matrix. To validate the method, a case study for a new aircraft cabin lining is conducted.Publicationtype: Doctoral Thesis1101 1980 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Reliability based design of unstiffened fibre reinforced composite cylindersUnstiffened lightweight cylinders are especially interesting for the space industry where high requirements in terms of controlling uncertainties and weight have to be met. Due to lack of experimental data, a deterministic design method based on a data basis containing only metallic cylinders is currently employed. Metallic cylinders show different characteristics as compared to cylinders made of carbon fibre reinforced plastics (CFRP) and hence the applicability of this method is restricted and the margin of safety achieved is unknown at early design stages. Within this thesis, 11 CFRP cylinders of equal layup are tested in axial compression and extensive measurements are taken on the micro, meso and macro level. These are used to develop a probabilistic design method that incorporates material, test and model related uncertainties. After identifying relevant parameters through a sensitivity analysis, a Bayesian framework is set up to update those parameters as soon as new measurements are available. These are used as input for a Monte Carlo analysis to compute a distribution function of the load bearing capacity of the structure. From this distribution function a safety factor covering material- and structural related uncertainties is calibrated. By employing a Bayesian multiplicative error model an additional safety factor is derived to address the uncertainty related to this method. The developed method offers the possibility to calibrate safety factors in dependence of the required reliability level and the a priori knowledge about material properties. Thus, a less conservative design can be pursued.Publicationtype: Doctoral Thesis931 1429 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Methodische Unterstützung der Entwicklung von Produktprogrammen mit hoher KommunalitätMegatrends of globalisation and individualisation characterize global markets. Hence, varying individual customer needs need to be satisfied and products need to be compli-ant with country-specific conditions while maintaining marketable prices. Offering a broad variety of products cost-efficiently, becomes a crucial success-factor. Yet, a broad variety of products leads to more complexity, causing more costs. These complexity costs incur for instance because of higher storage expenses, excessive logistics and smaller lot sizes. By developing modular product families, product variants can be con-figured from a small number of modules in order to reduce complexity. The modular design enables the use of common components in several product variants, so called commonality. In recent decades, several approaches have been developed to increase the commonality of product families, among others the Integrated PKT-Approach for Developing Modular Product Families. Still, additional potential can be exploited by using common modules even across product families. As there are no sufficient meth-ods for a product program wide approach yet, the aim of this contribution is to develop methodical support for the development of common product programs. This method includes the Carryover Chart (CoC), a newly developed visualisation of product programs regarding their carryover modules. At first potential carryover candi-dates are identified using the CoC. Analysing this potential as well as the actual needs for more commonality or more differentiation, a product program specific product structure strategy is developed. In accordance with this strategy the carryover candi-dates are developed as modules with common use across product families. This phase includes design for variety in order to achieve higher component commonality. The effect of higher component and module commonality on the product life phases is evaluated and optimized. These steps are supported by partly existing and adapted method units of the Integrated PKT-Approach. Resulting concepts are compared in a newly developed breakeven analysis in order to understand the effect on production and complexity cost. Applying the method on a product program of fork lift trucks and the design of base frames it is successfully evaluated. The Integrated PKT-Approach for Developing Modular Product families is extended by the new method to the Integrated PKT-Approach for Developing Modular Product Programs.Publicationtype: Doctoral Thesis2158 1517 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Systemanalyse und -synthese für die Auslegung varianter Leichtbaustrukturen unter dynamischen LastenThis thesis presents a newly developed methodical approach to support the dimensioning of variant lightweight structures under stationary dynamic loads. The approach supports the lightweight optimization with a simulation based prediction of the vibration behaviour for many product variants by coupling various dynamic substructures according to a modular product structure. The hybrid model used for this can consist of combined real test data with simulation models in the frequency domain. To obtain valid models for simulation based lightweight optimization of cabin interior various system identification tests have been per-formed of specimens ranging from sandwich panels to fully loaded galleys.Publicationtype: Doctoral Thesis968 2923 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Eine Methode zur Reduzierung der produktvarianteninduzierten Komplexität(2015); Durch unterschiedliche Entwicklungstrends, wie z.B. die Globalisierung des Wettbewerbs, dynamische Anforderungen an die Produkte und kürzere Produktlebenszyklen, stehen Unternehmen neuen Herausforderungen gegenüber. Diesen Trends wird häufig mit der Entwicklung von kundenindividuellen Produktvarianten begegnet, die folglich zu erhöhter produktvarianteninduzierter Komplexität führen. Unternehmen müssen sich daher mit der Fragestellung auseinandersetzen, wie diese Komplexität reduziert werden kann. Im Rahmen dieser Arbeit wird eine Methode zu ihrer besseren Beherrschung und Reduzierung entwickelt. Hierzu werden zum Einen strategische Handlungsfelder des Komplexitätsmanagements identifiziert und die Transparenz der Komplexität erhöht, indem sie erfasst und analysiert wird. Zum Anderen wird die Produktentstehung durch die Berücksichtigung der Komplexität bei der Weiterentwicklung und Optimierung einer Produktfamilie und der Auftragsabwicklung unterstützt. Die Methode wird zunächst anhand eines einfachen Beispiels erläutert. In diesem Beispiel sind die Problembeschreibung aus einer Expertenbefragung, weitere Erfahrungen aus verschiedenen Industrieprojekten und Hinweise aus der Literatur zusammengeführt. Der Praxisbezug wird anschließend durch eine Fallstudie in einem Unternehmen sichergestellt.Publicationtype: Doctoral Thesis2511 2324 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Montagegerechtes Produktstrukturieren im Kontext einer LebensphasenmodularisierungThe structuring of products is awarded with the highest potentials for assembly effort reduction of variant product families. A research in corresponding literature in the field of engineering design shows deficits of the approaches regarding systematic and consistent applicability in pre-development phase as well as consideration of product variety. In this dissertation a methodical procedure is evolved, that systematically transfers production knowledge and information into product development where it is applied for product structuring. Core element of the approach is a specially developed graphical tool, by this the actual product structuring task is performed. Therefore, the product structure and the assembly process are merged in a mutual graphical tool. In parallel, structuring measures are set up, that are formulated in the syntax of the graphical tool. By applying these measures within the tool, their impact both on the product structure and on the assembly process is directly pointed out. Thereby, an immediate evaluation of the product structuring is facilitated. For an enhancement of the evaluation a key figure system is used. The developed approach is validated within a case study application.Publicationtype: Doctoral Thesis1108 2654 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Auslegung von keramischen Strukturbauteilen unter mehraxialer statischer und zyklischer Beanspruchung(2013); Die Werkstoffwissenschaften haben in den letzten Jahrzehnten viele verbesserte und neue Materialien entwickelt. Viele Innovationen sind ohne neue Werkstoffe undenkbar. Zu diesen neuen Materialien gehören die Hochleistungskeramiken, die nicht nur thermische und elektrische, sondern auch mechanische Eigenschaften aufweisen, die für spezielle Anwendungen im Maschinenbau besonders geeignet sind. In der Produktentwicklung stößt der Werkstoff Keramik jedoch oft auf Unverständnis, da sowohl die Herstellprozesse als auch die Verbindungstechniken und Berechnungsverfahren von denen der gängigen Werkstoffe abweichen. In dieser Arbeit wird daher die Verwendung von Keramik im Maschinenbau systematisch aufgezeigt. Die Auslegungsgrundlagen der Bruchmechanik werden auf die Anwendungen im Maschinenbau übertragen, mit eigenen Versuchsdaten untermauert und in eine Auslegungsvorschrift überführt. Nach einem historischen Abriss über den Einsatz von Keramik im Maschinenbau werden die derzeitigen Auslegungsmethoden von keramischen Strukturbauteilen zusammengefasst. Es werden empirische Untersuchungen zur mehraxialen Beanspruchbarkeit von Oxidkeramik sowie Siliciumcarbid durchgeführt. Der Festigkeitsnachweis der FKM-Richtlinie des Forschungskuratoriums Maschinenbau wird als Grundlage genommen, um in einer analogen Vorgehensweise die Einflussfaktoren beim Konstruieren mit keramischen Werkstoffen aufzuzeigen. Zwei Anwendungsbeispiele - ein thermisch beanspruchter Stirling-Kolben sowie ein tribologisch beanspruchtes Radiallager - zeigen exemplarisch die konstruktiven Möglichkeiten der Produktentwicklung auf. Dieser Band der Hamburger Schriftenreihe Produktentwicklung und Konstruktionstechnik dient als Grundlage für die Konstruktion um keramische Bauteile in eine - meist metallische - Systemumgebung integrieren zu können.Publicationtype: Doctoral Thesis1123 7194 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Methodische Unterstützung der variantengerechten Produktgestaltung(2013); The aim of Design for Variety is to develop product families that provide a wide variety in the market with a minimum internal variety. For this purpose a method is presented which includes all stages of product development and is striving for a developed ideal of variant product families. This method is illustrated on basis of a practical example and validated in two case studies.Publicationtype: Doctoral Thesis3609 2794 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Eine Methode zur strategischen Planung modularer ProduktprogrammeThe Change from seller's to buyer's market leads to a high variance of individualized products for most companies. However, a high product variety usually leads to an increased complexity within the company. Therefore a key approach must be to align the offered external variety with market demands and to reduce the internal variety within the company. In this work, a new method for strategic planning of modular product programs is presented. In the first Phase of the method the existing product program is analyzed technically and economically. On this basis, scenarios for the future composition of the product range are developed and visualized. In the second phase concepts for program-wide takeover components are developed and evaluated based on performance indicators.Publicationtype: Doctoral Thesis2147 3161 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Eine Methode zur Entwicklung modularer Produktfamilien(2011); The dissertation presents a method for developing modular product families which differentiates between individual stages in the product lifecycle. Modularisation is first carried out for each stage, and the individual modularisations are then brought together to cover the full product lifecycle. This method allows for the development of modular product structures which not only simplify the configuration of product variants, but also fulfil the requirements of each stage in the product lifecycle.Publicationtype: Doctoral Thesis3810 7227