Engineering design in a different way: cognitive perspective on the contact and channel model approach

Engineering design often involves the integration of new design ideas into existing products, requiring designers to think simultaneously about abstract properties and functions as well as concrete solution constraints. Often designers struggle to reason with functional descriptions, while not fixating on existing solutions. This paper introduces the Contact & Channel Model (C&CM) approach, which combines abstract functional models of technical systems with the concrete geometric descriptions that many designers are familiar with. By locating functions at working surface pairs, they receive a concrete location in mental models. The C&CM approach can be applied to analyze existing product descriptions and synthesize creative new solutions for parts of the system or for entire new systems. At the moment the approach is being developed into an complete modeling and problem solving approach. C&CM has been used for several years in undergraduate engineering teaching at the University of Karlsruhe (TH) and is increasingly being introduced into industry by its use in research and development projects, by its students and its alumni

Analysis of running unlubricated friction pairings under permanent slip with an emphasis on advanced ceramic-steel pairings

Running clutches under permanent slip offers multiple applications regarding vibration damping or torque distribution in powertrains, for instance. Advanced engineering ceramics show specific benefits in wear behaviour and thermal resistance and are therefore representing an interesting chance for running unlubricated clutches under permanent slip conditions, as well. The emphasis of this analysis is the characterization of the tribological behaviour of the non-oxide ceramic/steel friction pairing SSiC/C45E regarding friction coefficient and wear. As to influencing factors, the sliding speed and contact pressure between the friction surfaces, as well as the specific energy dissipation are varied and analysed. The analysis results of running advanced engineering ceramics under permanent slip are very promising concerning system based friction coefficient level and stability as well as wear behaviour

Case study on prioritizing test cases and selecting the most qualified validation environment using an OEM’s transmission application as an example

Using the example of an Original Equipment Manufacturers (OEM) transmission application, it can be seen that large parts are currently being validated using real, physical prototype vehicles. Accordingly, validation in the automotive product development process (PDP) is taking place very late. In addition to this need for time optimization, another challenge is the complete validation of all variants of product generations in an OEM’s product portfolio with, among other things, increasingly divergent, country-specific engine/transmission combinations. An advance shift of validation activities via simulation or test benches into the Early Phase in the Model of PGE – Product Generation Engineering can compensate these current disadvantages so that more extensive test cases can be mapped at an early stage. The selection of the validation environment is influenced by various factors such as the time in the PDP and the associated possible accuracy or restrictions due to limited or inaccurate representation of the environmental system. The knowledge gained from the specification or the variation of solution-open elements (e.g. product properties and functions) in the early phase of PGE allows early identification of critical subsystems. Nevertheless, there is a lack of systematic approaches that supports the product developer in choosing the most qualified validation environment depending on the variation shares. In the context of the paper, a case study is used to show that existing approaches have so far not been able to support the product developer with sufficient accuracy in choosing the most qualified validation environment. Furthermore, research gaps in the prioritization of test cases in the context of the PDP are identified. Finally, a first approach is presented on how existing methodological approaches can be further developed and merged to close the identified gaps