FRPに関する計装化シャルピ衝撃試験における荷重時間履歴の解析

抄録

This paper describes a systematic approach for analyzing and processing the load data containing high frequency components caused by oscillation of a hammer in the instrumented Charpy tests of FRP. Special analytical and measuring techniques were used to separate such components and to smooth the jagged load line.
First, the digitized data of raw load time-history obtained from the Charpy tests on plain woven glass cloth FRP and chopped strand glass mat FRP were analyzed by means of the energy spectral density function to determine the cut-off frequency of a filter. Then the load data were passed through the recursive low pass digital filter and smoothed. Finally, the smoothed load line was fitted to a polynomial function of time by the least squares approximation with due consideration for precision in maximum load and ductility index.
The results of the analyses of experimental data and numerical values show that the high frequency components in load data are due to the interaction between the specimen and testing machine.