Carbon fibre sensor meshes: Simulation and experiment

Due to their very high strength and stiffness, carbon fibres are used for lightweight structures in aerospace and automotive industry as well as for other structures, where weight is essential for performance and effectiveness. Besides the outstanding strength and stiffness, some carbon fibres also show linear piezoresistive properties, so they can be used as strain sensor similar to standard strain gauges as well [4].When used as strain sensor, the measurement signal is an integral signal measured over the whole length of the fibre. The fibres can be arranged in special ways to measure two-dimensional strain fields over a larger area of a structure. The methods for analysing the strain signals and for determining the strain fields thereby are similar to the standard deformation formulations of finite elements. By using a linear or quadratic displacement ansatz, it is possible to determine the strain field over a large area, covered by those carbon fibre sensors.In this article the basic theory of the signal analysis is given and the results of an easy designed example are presented.

► Experimental in-plane strain field determination with carbon fibre sensor mesh.
► Linear and quadratic displacement approximation evaluates cell strains.
► Strain peaks detectable.