Problems related to the measurement of load signal in the instrumented Charpy impact test

摘要

The load calibration in instrumented Charpy impact testing was performed to develop an accurate measurement method of impact load. A decrease in specimen thickness results in a slight decrease of the calibration factors. This was attributed to strain localization near the region in which strain gages were attached. The results strongly suggested that the system must be calibrated for the different thicknesses of specimens to know the accurate impact load. The accurate impact load was not measured from the gage around the end of the slit which was introduced to release the constraining effect of deformation of the gage position from surrounding hammer; the effect of the vibration of the hammer appeared strongly around this position. However, it was possible to prevent the effect of such vibration by attaching the gage away from such position.