Matthias Messer

A Function-Based Approach for Integrated Design of Material and Product Concepts

Designing advanced multifunctional materials and products in an integrated fashion starting from the conceptual stage provides designers with increased flexibility to achieve system performance goals that were not previously achievable. Today however, product designers commonly select more or less advanced materials from selection charts or catalogs, rather than designing them along with the product from the conceptual stage on. In order to increase a designers flexibility and system performance in the conceptual stage and render conceptual materials design more systematic, hence less ad-hoc and intuitive, the main contribution is the development of a function-based systematic approach to the integrated design of material and product concepts from a systems perspective. This systematic approach is focused on developing multilevel function structures, including the material levels. Based on functional analysis, abstraction and synthesis, multiscale phenomena and associated governing solution principles are mapped to functional relationships. Hence, multilevel function structures are embodied into system concepts based on comprehensive identification and integration of phenomena and associated governing solution principles occurring at multiples levels of complexity and time and length scales. In this paper, the function-based approach to integrated design of material and product concepts is illustrated through the systematic design of reactive material containment system concepts. Having developed an overall reactive material containment system function structure, a more detailed function structure on the materials level is created. For dominating functional relationships at the materials level, governing solution principles are identified on multiple scales. The most promising solution principles are then classified in morphological charts. Combining solution principles in a systematic fashion including the materials level, principal solutions are identified. The most promising principal solutions, in other words the principal solution alternatives that narrow the gap to desired system performance goals, are selected and illustrated in concept selection charts. Finally, material and product system concepts are characterized in terms of its specific properties, which are to be tailored to the functional requirements and performance goals in subsequent embodiment design processes. Generating principal solution alternatives and hence developing concepts of the product and material as an integrated system, materials design becomes more systematic and hence less ad-hoc and intuitive. At the same time, designers are enabled to achieve system performance goals that were not previously achievable.

Model Selection Under Limited Information Using a Value-of-Information-Based Indicator

Designers are continuously challenged by complexity, as well as by the excessive instantiation and execution times of models, particularly in the context of integrated product and materials design. In order to manage these challenges, a systematic strategy for evaluating and selecting models is presented in this paper. The systematic strategy is based on value-of-information for design decision making. It consists of a (i) process performance indicator (PPI) to quantify the impact of model refinement from a decision-centric perspective and (ii) a method involving model evaluation. Using this method, a least complex but valid model is evaluated, and, only if necessary, gradually refined it until the most appropriate one is selected. The systematic approach is particularly well suited for integrated product and materials design, and all other scenarios where the perfect knowledge of the true system behavior and bounds of error are not available throughout the design space. The proposed strategy is applied to the design of photonic crystal waveguides for use in a next-generation optoelectronic communication system. In this paper, it is shown that the systematic strategy based on the PPI is useful for evaluating and selecting models particularly when accuracy of the prediction or the associated error bounds are not know.

Extending Reusable Decision -Centric Templates to Facilitate Collaboration Using Game Theory

Modular, executable, decision -centric templates have been used as a means to model design processes computationally. The use of decision templates has been limited so far to decision making by a single stakeholder . Templ ates for multiple stakeholders, making concurrent decisions regarding the design of a product have not been developed . In this paper, we extend the current template -based approach using Game -Based Design , which is a method incorporating game theoretic prot ocols in engineering design and has been proposed as a means to solve design decision problems for multiple stakeholders. The interaction s bet ween multiple decision makers are modeled using cooperative, non -cooperative, and leader follower protocols . The p roposed approach facilitates collaboration between two stakeholders by organizing design process information u sing decision -centric templates . The proposed approach facilitates computational modeling of designer interactions in a distributed environment by capturing the dynamics of collaborative decision making. It is demonstrated with respect to facilitating the design and prototype manufacture of a separation channel for a microscale gas chromatography system.

Extracting the Structure of Design Information From Collaborative Tagging

Information representation in engineering design is currently dominated by top–down approaches such as taxonomies and ontologies. While top–down approaches provide support for computational reasoning, they are primarily limited due to their static nature, limited scope, and developer-centric focus. Bottom–up approaches, such as folksonomies, are emerging as means to address the limitations of top–down approaches. Folksonomies refer to collaborative classification by users who freely assign tags to design information. They are dynamic in nature, broad in scope, and are user focused. However, they are limited due to the presence of ambiguities and redundancies in the tags used by different people. Considering their complementary nature, the ideal approach is to use both top–down and bottom–up approaches in a synergistic manner. To facilitate this synergy, the goal in this paper is to present techniques for using dynamic folksonomies to extract global characteristics of the structure of design information, and to create hierarchies of tags that can guide the development of structured taxonomies and ontologies. The approach presented in this paper involves using (a) tools such as degree distribution and K-neighborhood connectivity analysis to extract the global characteristics of folksonomies and (b) set-based technique and hierarchical clustering to develop a hierarchy of tags. The approach is illustrated using data from a collective innovation platform that supports collaborative tagging for design information. It is shown that despite the flat nature of the folksonomies insights about the hierarchy in information can be gained. The effects of various parameters on the tag hierarchy are discussed. The approach has potential to be used synergistically with top–down approaches such as ontologies to support the next generation collaborative design platforms.

Robust and optimum designs of non-linearly tapered slow light couplers

In this work, optimum and robust designs of non-linearly tapered slow light couplers are explored. An optimum design yields a set of design parameters that would result in the best transmission. A robust design yields a set of design parameters that would result in good coupling and low transmission variation in the presence of random fabrication errors. It is shown that the uncertainties in the flat dispersion region affect device transmission more strongly than uncertainties in the linear dispersion region of the coupler. Therefore, moderate-length couplers with relatively longer linear dispersion regions yield more robust performance.

Domain Independent Approach to Designing Hierarchical Platforms on Multiple Levels of Abstraction and Scales

In this paper, we propose a domain independent approach to realizing hierarchical platforms using numerical taxonomy. Hierarchical product platforms present a form of competitive advantage by introducing standardization on multiple assembly levels. However, we believe that numerical taxonomy can also be used to identify hierarchical platforms on multiple length and time scales and consequently facilitate the design of complex engineering systems in any domain. Therefore, in this paper we present a domain independent approach to hierarchical platform design. This approach is then applied to develop a hierarchical product platform for a family of offshore vessels. In this study, we focus on how to use numerical taxonomy to develop a bracket platform in the midship section. Finally, we critically evaluate the usefulness of the proposed domain independent approach concerning the realization of complex engineering systems through hierarchical platform design not only on multiple assembly levels, but also multiple length and time scales.Copyright

Designing Embodiment Design Processes Using a Value-of-Information-Based Approach With Applications for Integrated Product and Materials Design

Designers are continuously challenged to manage complexity in embodiment design processes (EDPs), in the context of integrated product and materials design. In order to manage complexity in design processes, a systematic strategy to embodiment design process generation and selection is presented in this paper. The strategy is based on a value-of-information-based Process Performance Indicator (PPI). The approach is particularly well-suited for integrated product and materials design, and all other scenarios where knowledge of a truthful, i.e., perfect, design process and bounds of error are not available in the entire design space. The proposed strategy is applied to designing embodiment design processes for photonic crystal waveguides in the context of a next-generation optoelectronic communication system. In this paper, it is shown that the proposed strategy based on the Process Performance Indicator is useful for evaluating the performance of embodiment design processes particularly when accuracy of the prediction or the associated error bounds are not known.Copyright

Matrix-free plane wave modal expansion approach for robust design of photonic structures

Fourier operator is used in the vectorial Helmholtzpsilas equation for the calculation of layer modes in a 2D slice of a photonic device. The slice modes are then propagated throughout the device via scattering matrices.

Designing Embodiment Design Processes for Blast Resistant Panels

Designers are continuously challenged to manage complexity in embodiment designprocesses, in the context of integrated product and materials design. In order to manage complexity in design processes, a systematic strategy to embodiment design-process generation and selection is presented in this paper. The strategy is based on a value-ofinformation-based Process Performance Indicator. The approach is particularly well-suited for integrated product and materials design, and all other scenarios where knowledge of a truthful design-process and bounds of error are not available in the entire design space. The proposed strategy is applied to designing embodiment design-processes for multifunctional blast resistant panels. It is shown that the proposed strategy based on the Process Performance Indicator is useful in assessing the performance of embodiment designprocesses particularly when knowledge of prediction accuracy or its error bounds is not known throughout the whole design space.