DYNAMIC MEASUREMENTS FOR THE STIFFNESS CONSTANT OF A POWDER BED

A measuring apparatus was devised to determine the dynamic physical pr operties of a powder bed from the transfer function of vibration accel eration that results from the direct application of random vibration t o the powder bed. By using this apparatus, the variation of the stiffn ess constant of a powder bed with various vibration forces and compres sion forces was measured. The stiffness constant gradually decreased w hen the vibration force exceeded a certain value. With respect to the change in stiffness constant with compression force, the following exp erimental equation was derived: k=SW(n), where k is the stiffness cons tant of a powder bed, W the compression force applied to the powder be d, and S and n are empirical constants.