A fundamental relationship between force waveform and the sound radiated from a power press during blanking or piercing

A relationship between the equivalent continuous noise level Leq received near a machine structure and the derivatives of its transient excitation history has been derived from fundamental principles. Data from a multi-parameter study of power press tooling has been used to test this relationship, which is shown to be in essential agreement (95% confidence interval) with the regression line prepared from the data. The results indicate that the effects of tooling changes on Leq can be evaluated separately from the effects of structural changes, and that changes in Leq brought about by tooling changes can be estimated without knowledge of the vibration and acoustic properties of the structure and enclosure.