Development of Piezoelectric Vibration Sensor to Analyze Building Vibrations

When buildings are exposed to vibration or shock, those buildings can be damaged partially or fully depending on the vibration energy. Therefore, quantitative analysis of building vibration has become popular among researchers. In this research, vibration sensor was developed using piezoelectric ceramic cantilever beam and tip mass to confirm the vibration frequency of the building does not exceed the cosmetic damage range. As the first step, mathematical model was derived to calculate the resonance frequency of cantilever beam with a tip mass. At the resonance frequency, maximum amplitude could be achieved resulting a higher output voltage of piezoelectric sensor. The derived mathematical model and finite element analysis were used to determine the accurate dimensions of the cantilever beam based piezoelectric sensor. 31 coupling mode was used to measure the voltage difference in piezoelectric material. Faster Fourier Transformation function was used to analyze the signal. Output voltage of piezoelectric sensor was calculated using finite element analysis at vibration frequency range that corresponds to cosmetic damage. According to the calculations, threshold voltage level and frequency of sensor are 4.35mv and 9.5Hz respectively to activate the alarm. Finally, by using a vibration source, comparatively high accuracy of 92% voltage value was obtained from the prototype device compare to the software modelling. The developed sensor module is capable of indicating harmful vibrations on building structures.