Entwicklung und praktische Evaluation einer Methodik zur Identifikation und Bewertung branchenspezifischer Kennzahlen für die Additive Extrusion von endlosfaserverstärkten Werkstoffen

Abstract

In the last decade, the application of additive extrusion processes has become established in many industrial sectors. One of the more recent process modifications is the additive extrusion of continuous fibre reinforced materials. For potential users, it is important to check whether the manufacturing process is fundamentally suitable for their application and which specific process best meets the respective requirements. As a technology platform of the Institute of Composite Structures and Adaptive Systems of the German Aerospace Center (DLR), the Innovation Lab Empower Additive Extrusion aims to support potential users in answering these questions and to simplify access to additive extrusion technologies for the broad industry. For this purpose, among other things, a five-stage evaluation procedure is made available. The aim of this master thesis is to establish and evaluate a methodology for identifying and assessing industry-specific key figures for the additive extrusion of continuous fibre-reinforced materials in order to incorporate the findings into the development of the five-stage assessment procedure. In order to achieve reliable results, the focus is on an evaluation of the key figures by potential technology users. Potentially relevant key figures have been compiled by the German Aerospace Center. These key figures are summarised in individual key figure groups. The clarity gained in this way should make it possible for inexperienced technology users to identify key figures that were previously unknown to them. In addition, the key figure clustering should make it possible to classify entire groups as irrelevant on the basis of the designation of the individual groups in order to minimise the evaluation effort. The clustering of key figures is based on existing clusters. A three-stage evaluation scale is created to evaluate the indicators, as is also used to evaluate requirements in product requirements documents. Finally, it is shown how the industry-specific relevance of individual indicators can be worked out from the assessments of different technology users. The established methodology is evaluated by means of expert interviews and a quantitative survey during a workshop. The results of the evaluation indicate that the established evaluation method can be classified as well applicable. In the expert interviews, interdependencies between the indicators were noted across all indicator groups. According to the outcome of the quantitative survey it is not practicable to clearly assign the indicators to an indicator group. The procedure of excluding complete groups of indicators from the evaluation based on their designation is considered problematic due to these results. Given the small number of respondents, the results are limited in terms of their generalisation to the population under consideration. All in all, the results of the master thesis demonstrate that standards for the classification of process and material properties should be defined in the future. In addition, the interdependencies of the key figures should be considered and presented in more detail.