Experimental and numerical modal analysis of the plate of glass composite

The given paper is closely connected with the experimental modal analysis of natural frequencies of glass composite material. In relation to the tested glass composite, modal analysis was performed by help of special measuring device Pulse 12. The mentioned device was supplied by company Bruel & Kjear and the experimental measurements were carried out using damaged and undamaged plate sample which were prepared from the mentioned material hereinbefore. The investigated and analyzed plates of glass composite were made of six layers of glass fibres and they were arranged under the angle 90° (it is like fabric material made off glass fibres). The layers arranged in the given way were joined by epoxide resin MGS 285. The experimental measurement of natural frequencies of glass composite plates was carried out using the undamaged and damaged sample with proportions 78 mm x 78 mm while ten measurements were performed for each one specified site of the sample. In relation to the damaged plate sample, there was the circular cut-out with the diameter 6 mm in the centre. The finite element method in the software system ADINA v.8.6.2 was used for numerical analysis of the natural frequencies. According to the comparison of frequency response for undamaged and damaged sample, it can be concluded that the natural frequency of the damaged sample is less than the natural frequency of the undamaged sample. The measurement range for frequencies was up to 14 000 Hz.