Application of Ultrasonic Testing for Detecting Defects on Wooden Rafters in Ancient Building

摘要

Introduction Ultrasonic test methodology and analyzing process were studied for the purpose of detecting defects in rafter members of ancient wooden building. Normally, rarer members are buried or attached with the ceiling of the roof and this aspect makes it hard to apply the normal transmission method. Moreover, deterioration of this member normally starts and/or progresses at the attached or buried parts. For solving these problems, in this study, indirect test methodology of ultrasonic test was proposed and analyzing methods including time and frequency domain analysis were also proposed. Normal TOF (Time of Flight) analysis found out to be difficult to derive reliable results while the frequency domain analysis with FFT (Fast Fourier Transform) and BPF (Band Pass Filter) showed high possibility of detecting defects. Energy analysis of received ultrasonic signal is now on process with additional devices.