Indian Journal of Science and Technology

Abstract

Objectives: This paper presents a health monitoring criteria development aspect based on the frequency response spectrum under axial compressive load on wooden samples. Methods/Statistical Analysis: The compression tests are performed on different wooden specimens as per IS:1708 (Part VIII and IX):1986. The impact echo test is conducted at certain load intervals under increased compressive load and the frequency spectrum was monitored. A MATLAB based code is used to calculate the dominant frequency values of the sound signals corresponding to each impact echo test. The graphs for frequency and compressive load are plotted for different samples. Findings: Interesting conclusions were obtained from the frequency plots under compressive load before failure and after failure. It was observed that loading decreases the frequency values. But at the point of initial major crack, frequency was increased due to length reduction. Applications/Improvements: A health monitoring criteria can be developed based on the frequency response trends by observing these increased value of frequency when tested on the wooden samples. The damaged and undamaged state were predicted successfully. 
Keywords: Compressive Load, Frequency Response Spectrum, Health Monitoring, Impact Echo Test, MATLAB