Parametric Model Generation and Sizing of Lightweight Structures for a Multidisciplinary Design Process

Kurzfassung

The product development cycles in all parts of the industry become increasingly shorter. In spite of the shorter cycle time, the performance of a new product generation must be increased. In the early design process, simulation tools are used to create a large number of designs and to evaluate their performance. To reduce the effort for modeling and structure evaluation, a design environment for thin-walled lightweight structures (DELiS) with the focus on structure mechanics has been developed. The core of DELiS is a parametric model generator which creates models of lightweight thin-walled structures. It has been developed initially for the aircraft pre design process. Furthermore, due to its flexibility and the use of synergies to aircraft wings, wind turbine blades can also be generated with DELiS. Based on the same abstract database, it is possible to create models with variable level of detail. Exemplarily wings can be modeled as simplified beam, or in a fine wing model, stringers can be created using beam elements or smeared as an extra shell layer. With the support of several com-mercial finite element (FE) solvers many other applications can be used, such as sizing tools that require a specific FE solver. Thus, DELiS facilitates interfaces to these sizing tools. So forth it includes the modeling, the simulation and the evaluation process. Based on Python programming language it is platform independent and can access most major libraries. The structural description of a database is interpreted and transferred in an abstract object oriented data model. Therefore, new interfaces can be added conveniently, FE models can be derived smoothly and sizing results can be used to update the model easily. DELiS utilizes the common aircraft language CPACS (Common Parametric Aircraft Configuration Scheme) as input database for the model generation. It is developed by the German Aerospace Center (DLR) and allows the exchange of data between all disciplines in the aircraft design pro-cess. By interpreting this multidisciplinary aircraft language, all disciplines of the aircraft design process are able to communicate with the structural model in such problems. When searching for the game changing configuration of aircrafts or wind turbine blades, a wide design space must be supported. This design space consists of global (e.g. different configurations) as well as local (e.g. subcomponent properties) degrees of freedom. Thus, a modular and parametric design environment is advantageous. The paper shows the program architecture and the methodology of DELiS that enable the required variability. Examples of the model generation are given and the flexibility with respect to sizing tools is pointed out.