consultant on mechanical testing, Scotia, NY
Pages: 15 Published: Jan 1990
Different measuring techniques were used to determine some of the specified characteristics of nine Charpy impact machines. In general, the techniques used were specified or recommended by one or more national standards. For example, the elevation of a raised pendulum was determined by direct measurement with a ruler and also by calculation from the measured angle of the pendulum rod. Both methods gave equal values with about the same reproducibility. On the other hand, significant differences were found when the friction loss in the pendulum was measured by a single swing and by multiple, successive swings. Significant differences in the period of oscillation were also found when the maximum angle of swing was 15 degrees as compared with 5 degrees. Both values were specified as permitted maximums in some national standards.
impact machines, Charpy machines, friction loss, period of oscillation, clinometer
Paper ID: STP24136S