• Steinbild, Philip Johannes
• Sauer, Sebastian
• Winkler, Anja
• Modler, Nils
• Bätzel, Tim
• Matassini, Lorenzo
• Woog, Matthias
• Lehmann, Florian

Abstract

A decisive factor in achieving the climate targets of the German government is the reduction of CO2 through the gradual electrification of transport. In battery-electric vehicles, the energy storage system is typically positioned close to the ground under the passenger cell. Thus, the crossing of obstacles or typical load scenarios affecting the underbody play a crucial role for vehicle safety. Currently, such battery protection structures usually consist of thick-walled aluminum, steel or titanium constructions, which results in increased weight and manufacturing costs [1]. Higher moving masses in battery electric vehicles lead to high resource consumption in their life cycle. In this context, battery protection structures represent lightweight structures that are safety critical parts protecting the battery system from impact events and medial influences. Additionally, these parts are in general large-scale parts, which show a high potential for mass reduction and functional integration of a conditions monitoring system. Therefore, the focus of the presented paper is on the development of a functionally integrative lightweight battery protection structure, which consist of a sandwich lay-up of glass fiber reinforced plastic (GRP) cover sheets and polymeric foam in the middle. In addition to the purely mechanical protection of the energy storage unit, this structure should be able to detect and classify any damage occurring of the battery module above it caused by impact events. Thus, a structure-integrated sensor system is also focused, which shall be used for the determination of the extent of damage, which means that service activities or component replacements will only be carried out when necessary and not within predefined maintenance intervals. Based on a detailed requirement profile for the structure, a comparison of selected sensor concepts is carried out. For further investigations, three sensor types (pressure sensor, strain sensor, inductive sensors) are selected and examined in more detail. Thus, investigations in regard to the sensor positioning in the composite lay-up and the ability for detecting different load cases were planned and carried out. A further issue is the clarification of possible integration options in terms of manufacturing technology. For this purpose, the so-called e-preforming technology is used, which enables an automated application of functional elements. Therefore, different types of conductor track manufacturing and contacting of electronic components within the sandwich structure are investigated. The results of these initial investigations in the case of automotive applications show a high potential to be transferred to applications in the aviation or aeronautical industry. In particular, these also influence the approaches for the design and development of structural health monitoring components and systems.

Topics

• impedance spectroscopy
• polymer
• aluminium
• glass
• glass
• steel
• composite
• titanium