Methodik zur Identifikation von anforderungsoptimalen Konfigurationen an Multi-Material-Bauweisen

  • Identification process of optimal configurations for multi-material-structures

Ngahane Nana, Liliane G.; Feldhusen, Jörg (Thesis advisor); Löwer, Manuel (Thesis advisor)

Düren : Shaker Verlag (2020)
Book, Dissertation / PhD Thesis

In: Schriftenreihe Produktentwicklung und Konstruktionsmethodik 31
Page(s)/Article-Nr.: IX, 133 Seiten : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2020


The design of technical structures is becoming more and more complex and competitive, and this is not going downhill. That is, the structures to be designed must fill in more and specifications. Among the challenges, light construction is of great importance. This gave rise to the development and the elaboration of a significant number of materials in order to be able to design structures but providing performances as interesting as structures having been designed with steel, because the simple fact being light is not interesting overall. Despite the abundance of already existing materials, it should be noted that the three-dimensional section through the properties of the materials represented in the diagrams presented in the work of Prof Ashby present empty areas. These gaps are signals that mark the need to create new materials to cover all the diagrams. Design engineers do not always have the necessary knowledge sufficient to be able to overcome this need, nor always the time to wait for new materials to be created, therefore turn to the concept of multi-material structures which also allow, to fill these gaps. In the framework of this doctorate, a methodology was developed to help in the design of multi-material structures fulfilling very precise and sometimes discordant performances. This methodology uses a combination of three elements, namely an architecture database, a material library and an optimization algorithm which, depending on needs, determines which materials must be combined in which arrangements in order to obtain certain properties for a product to be designed. The basic architectural database contains the usual multi-material architectures from which the designer can choose, it can be supplemented at any time in order to be able to resolve the problem posed. The material library contains the materials available or to be acquired; it is important that all the properties necessary for the calculation of the required functions are entered in this library. The optimization algorithm is the element which makes it possible to combine the different materials in order to build the architectures which are of interest for the case considered, to evaluate the different combinations and to eliminate those which are not relevant for the structure to develop. The result of this methodology is the delivery of a list of potential structures with their respective properties that meet the requirements defined in the specifications. The final choice of the structure to be designed can be made directly following a brief analysis of the solutions delivered. Depending on the number of solutions provided and the properties of each solution compared to the other solutions, a more elaborate analysis may be required to make the final choice. In this case an analysis algorithm should be coupled to the methodology developed in this work.