In-situ stress analysis of fiber reinforced plastics under bending load until failure by using integrated textile-based piezoresistive sensors

Abstract

The application of fiber reinforced composites (FRC) for load-bearing and safety-relevant components requires regular inspections to assess the structural conditions. A suitable solution are integrated textilebased piezoresisitive sensors for structural health monitoring applications. This research work focusses on the evaluation and comparison of the electromechanical strain sensing behaviour of steel wires and carbon fibers on the fiber and composite scale. The electromechanical properties are investigated by using a uniaxial fiber tensile test with a simultaneous electrical resistance measurement. Glass fiber reinforced plastic (GFRP) specimen with in-situ sensors are tested in quasistatic and cyclic three-point bending tests. The acquired sensor signals are used for a comprehensive stress analysis and better understanding of the failure behaviour. The cyclic testing procedure showed reproducible sensor signals.