NASA Note Says Measured Hammer-Tap Inputs Remain Valid Despite Irregular Force Shapes

A NASA technical brief from Langley Research Center addresses instrumented hammer testing. It argues that such tests do not need to follow an idealized single half-sine force waveform. The authors note that crest ripples and separated contacts are acceptable as long as the full force and response are measured accurately. According to the brief, a change in force shape alters the excitation but does not by itself make the test record invalid. Contact details for lead contact Joel W. Sills are provided for further information.