SCFRP

Carbon fiber reinforced composites (CFRP) offer superior weight-specific mechanical properties. However, their brittle failure behavior limits the structural integrity and damage tolerance in case of impact and crash events. Furthermore, their electrical conductivity is insufficient for certain applications (e.g. lightning strike protection, grounding). A promising new approach is the incorporation of highly conductive and ductile continuous metal fibers into CFRP. The basic idea of this concept is to merge the beneficial properties of CFRP and metal materials in a joint composite. The present study focuses on optimizing the structural and electrical performance of such hybrid composites with different shares of metastable austenitic steel fibers (alloy: 1.4301, filament diameter: 60 µm). Supported by analytical and numerical investigations, a wide range of experimental tests was conducted on single fibers as well as on unidirectional and multiaxial hybrid laminates. Within this DFG project, synchronous improvements of the electrical in-plane conductivity, the plain tensile behavior, the impact and penetration resistance as well as the notched properties were verified. In addition, the usability of the embedded steel fibers for non-destructive testing by measurement of deformation-induced phase transformation via proper magneto-sensor devices was demonstrated. Based on the outcome of the analyses, load-case dependent design principles for an optimized arrangement of the metal fibers were derived.