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[EN] Ferroelectric materials exhibit a phase transition to a paraelectric state driven by temperature - called the Curie transition. In conventional ferroelectrics, the Curie transition is caused by a change in crystal symmetry, while the material itself remains a continuous three-dimensional solid crystal. However, ferroelectric polymers behave differently. Polymeric materials are typically of semi-crystalline nature, meaning that they are an intermixture of crystalline and amorphous regions. Here, we demonstrate that the semi-crystalline morphology of the ferroelectric copolymer of vinylidene fluoride and trifluoroethylene (P(VDF-TrFE)) strongly affects its Curie transition, as not only a change in crystal symmetry but also in morphology occurs. We demonstrate, by high-resolution nanomechanical measurements, that the semicrystalline microstructure in the paraelectric state is formed by crystalline domains embedded into a softer amorphous phase. Using in situ X-ray diffraction measurements, we show that the local electromechanical response of the crystalline domains is counterbalanced by the amorphous phase, effectively masking its macroscopic effect. Our quantitative multiscale characterisations unite the nano- and macroscopic material properties of the ferroelectric polymer P(VDF-TrFE) through its semi-crystalline nature., European Union’s Horizon 2020 research and Innovation programme under the Marie Skłodowska-Curie grant agreement number 721874 (SPM2.0). RG acknowledges funding from the European Research Council ERC–AdG–340177 (3DNanoMech). This work was supported by the UK government’s Department for Business, Energy and Industrial Strategy. The dynamic mechanical analysis was supported by T. Koch from the Institute of Materials Science and Technology, TU Wien. We gratefully thank A. Muhamedagić for the contribution of artworks to the figures (armindesign.li).

Thesis (PhD)--University of South Australia, 2011. The key research issues addressed in this dissertation are the integration across functional areas of the engineering design process through process modelling and knowledge representation via ontologies.

Refereed/Peer-reviewed

Complex design processes often embrace various degrees of virtual development, where complex models and simulations replace traditional construction and testing of physical models. However, as the number of models and their inter-relationships grows, managing processes and models becomes increasingly difficult. We describe how to support product development by applying ontologies to manage and guide the design of simulations and to make domain knowledge readily available though context-specific reuse mechanisms. Based on established engineering standards like ISO 10303 we defined domain-specific abstractions and operators to facilitate information reuse.

The ISO-10303 standard, called STEP, originated in 1984 and published in 1994, has been adopted by many industries including shipbuilding, aerospace and automotive. This paper throws new light on the well established standard by investigating the suitability of STEP to support the exchange of parameterised models between CAD systems. The paper points out how design intent, i.e. parameters, constraints and constructional history of a model, can be transferred to another system and it explains why the new enhancements of STEP which were published recently are able to ease the migration of a STEP-based model. The implications of these enhancements on the integration of the automotive design environment are outlined shortly and provide a showcase of these refinements.

Factoids—a word coined by Norman Mailer in his introduction to Marilyn—are mere speculations or guesses which have been repeated so often that they are eventually taken for hard facts. There is something decidedly unbiological about such factoids: the tendency to get stronger the longer they live is one of their most insidious qualities. Factoids occur in all branches of scholarship and many are of course still well disguised—their complete discovery would create havoc in the subjects concerned. Archaeology, converted from treasure hunting into an historical discipline, is for obvious reasons prone to create a number of factoids.The process by which mere hypotheses attain the apparent rank of established fact, without ever having been proved, presents a linguistic and a psychological aspect. Linguistically, words or particles indicating the hypothetical character of a statement are dropped one by one in a process of constant repetition. The subjunctive is exchanged for the indicative, and in the end the factoid is formulated as a straightforward factual sentence. Psychologically, the repetition of unproved hypotheses is facilitated by an attitude which is as indispensable in research as it is ambivalent: a certain amount of implicit trust in the results of other scholars' research.

The integration and reuse of simulation and process information is not wellintegrated into current development practices. We introduce a framework to integrate Multidisciplinary Design Optimisation (MDO) processes using ontological engineering. Based on a multi-disciplinary design scenario drawn from the automotive industry, we illustrate how semantic integration of process, artifact and simulation models can contribute to more effective optimisation-driven development. Ontology standards are evaluated to assess where existing work may be applicable and which aspects of MDO processes require further extensions.