Fibre optic shock velocity sensor for solids

Abstract

This paper reports a fibre optic sensing technique for the measurement of shock velocity in solid materials. The shock-induced changes in the light transmission properties of an optical fibre are employed as the principal transduction mechanism. A polycarbonate flyer plate generated shock waves by impacting a perspex target. The shock velocity was determined from the difference in arrival times of the shock front at the spatially separated optical fibres embedded in the target. The main advantage of this sensor system lies in its simplicity and immunity to optical and radio frequency (RF) noise. Consideration is also given to the effect of release waves on the uniform shock pressure region generated by the ˚yer impact which can degrade the accuracy of the velocity measurement.