Laser-based application of diffraction grating sensors for full-field strain measurements during the manufacturing process of a composite structure

Diffraction grating sensors are used for strain measurements and can also be used for displacement, velocity or vibration measurements. Conventionally, this requires applying thin-film diffraction gratings to the structure, which is cumbersome and lacks reproducibility. The utilization of these gratings for an industrial use by means of Direct Laser Interference Patterning for structuring a metal surface and moulding these onto a composite structure is investigated. Therefore, the metal surface and the produced composite surface is optically evaluated. The results show, that the optical properties where successfully transfered and that the method can therefore be used for a cost-efficient application of diffraction grating sensor onto composite specimens or components. • Method for the cost-efficient application of an optical measurement surface to composite. • Use of Direct Laser Interference Patterning for preparing a steel mould. • Moulding a diffraction grating-based sensor into GFRP and CFRP. • Optical properties are successfully transferred from steel to a composite surface.