Dynamic measuring of force-displacement-characteristics of shockmounts

Shockmounts are widely used to isolate sensitive equipment from vibrations and mechanical shock. Despite the highly dynamic nature of shock events, the force-displacement-characteristics of shockmounts which are provided by manufacturers are gained by static measurements. Therefore, this paper presents a dynamic mechanical model of a setup for dynamic measurements of force-displacement-characteristics. The model bases on acceleration measurement of an inert loading mass, which displaces the shockmount, when the arrangement gets excited by means of a shock test machine. The influence of the shockmount's mass in measuring setup is considered as well as special needs for handling measurements under shear or roll loading. A method for allocating the measured force data on the displacement axis is developed. An equivalent of a hysteresis-loop in a decaying force-displacement-diagram is proposed. Based on exemplary measurements, error calculation and statistical analysis show the qualification of the proposed method for attaining dynamic FDC.