Dünne CFK-Schaum-Sandwichstrukturen - Bewertung unterschiedlicher Fertigungsmöglichkeiten

Research output: ThesisMaster's Thesis

Abstract

Since World War II, engineers have taken advantage of core composite structures. Even then, the British fighter-bomber "Mosquito" was made in sandwich construction. The targeted combination of core and outer layers can combine properties such as high rigidity, low weight and thermal and acoustic insulation. In previous applications of sandwich composites, the core layer is thick compared to the top-sheets. Due to new market segments, especially sandwich construction is of interest, in which the core is not significantly thicker than the cover layers. This material combination is referred to as microsandwich by 4a manufacturing GmbH. The aim of the present work is to investigate and evaluate the processability of these materials. The cover layers of the micro sandwich panels consist of 200 g/m2 twill weave carbon fiber fabric and the core layer is a closed-cell Polymethacrylimide (PMI) plastic. The microsandwich panels of the present work were produced by the methods prepreg hot pressing, vacuum assisted resin infusion (VARI) and resin transfer molding (RTM). The measured material properties were compared in a pairwise comparison. This resulted in a ranking of the procedures and the process settings with respect to density, bending properties and peel strength. Based on information from the literature and the sandwich properties, a SWOT analysis of the procedures was prepared. It turns out that every process has advantages and disadvantages. While the RTM core composites provided the highest bending strengths, the prepreg sandwich panels achieved the best stiffness rating. The VARI process results in micro-sandwich panels with high interlaminar strength. In parallel to the evaluation of the material properties, a method was developed, so that a shock in the foam core could be laminated.

Details

Translated title of the contributionThin CFK-foam sandwich structures - evaluation of different production possibilities
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date19 Oct 2018
Publication statusPublished - 2018