Measuring the impact force from the ISO impact ball and comparison with the tapping machine and alternate input method

Abstract

The impact ball was recently standardized within the ISO standards as a low-frequency input impact source for impact testing of floor-ceiling assemblies. The input force due to an impact ball is not measured during the tests. A force measurement plate was created with three force transducers to measure the impact force due to ball drops on six different floor assemblies. The input force showed a really good comparison for heavy and lightweight floors in lower frequency but poor force excitation for all the floors above 100 Hz. The input force values were compared with a modified tapping machine's force input levels showing the tapping machine has poor low-frequency excitation (in comparison) but an improved high-frequency excitation. An alternate input method was developed where a force transducer is added to the impactor to make live measurements of the input force and the impact tip can be changed to modify the range of targeted frequencies for any test.