Fibre optic sensing based on the Rayleigh signal analysis support the investigation of the deformation behaviour of structures in a comprehensive manner. Glass fibre sensors applicated on the surface of any solid or soft material as well as embedded in composites, provide a high-resolution strain measuring. Compared with equidistant strain measurement such as Strain Gages, the fibre optic sensing enables a smooth progress of strain along the fibre axis with high local resolution. The study shows the applicability of fibre optic sensors on glass surfaces and the determination of the interlaminar behaviour of polymeric interlayer material under static and thermal load. The elastic parameters depending on time, strain and temperature are examined on large-scale specimen in bending tests and compared with standard tests on small scale specimen. The results show, that the standard tests give proper initial values of the pure interlayer material. However, the structure-related effects of composite panels like the locking effect or the restraint of lateral extension can be captured more detailed using different large-scale tests. In addition to the small-scale tests the large-scale tests show a decreasing statistical dispersion caused by large effective area of investigation. In conclusion fibre optic sensing provides a powerful method for the experimental investigations of the thermo-mechanical behaviour of polymeric interlayer materials in the laminated state. Both, the determination of the mechanical behaviour of polymeric interlayer materials in glass laminates and the evaluation of the numerical model can be used as a basis for computer-aided analysis of building structures.