Detection of the deformations in ceramic plates with coherence analysis and transfer function model

In this study, in order to detect the deformation in ceramic plates, a new measurement method has been identified. In the measurement system, exerting impact on the ceramic plates that have the same features and size, sound data coming out of the ceramic plates because of the impact were recorded. Based on the obtained data, a correlation analysis was made according to the strong and cracked situations of ceramic plates. In the analyses, it became possible to divide the coherence frequency range into two zones. The first one of these is the part at small correlation levels representing low frequency zone and it is placed under spectral amplitudes which are approximately defined at 0.2 coherence level. This zone is nearly between 0-28 kHz frequency ranges. In this frequency range it was observed that there is a weak relation between the spectrums of healthy and cracked ceramic plates. The second part, was however, defined between 0.2 and 0.7 coherence levels. In this experimental study, correlation analysis clearly determined in which frequency range the defected plates would react to sound waves.