A method of measuring the cable tension force with the application of smart phones
Chen Shuang-rui1, Yan Quan-sheng1
COMPUTER MODELLING & NEW TECHNOLOGIES 2013 17(5D) 11-18
1 School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong Province, China, 510640
Smart Phones are portable and extensible, besides they can provide MEMS micro-accelerometer with good support. This article introduces a method of measuring the tension force of the cable-stayed bridge with the application of a Smart Phone. According to the FFT (Fast Fourier Transform) algorithm, the time domain is converted to the frequency domain while we program on the Android platform and the effective peak-picking algorithm is designed to determine the natural frequencies of the cables. An analysis of simulated signals demonstrates that the designed programs can accurately identify the natural frequencies with or without the disturbance and it can also compute the fundamental frequency based on the identified natural frequencies. With the fundamental frequency it goes on to calculate the tension force. A comparison of the result by adopting the method introduced in this article and the one collected from the JMM-268 tension force dynamic measuring instrument indicates that the Smart Phone has some difficulty in measuring the cables shorter than 40m; however, a less than 5% error is detected where the cables are longer than 40m.