High-speed impact test using an inertial mass and an optical interferometer

Abstract

A high-speed impact testing method for evaluating mechanical properties of materials is proposed using an inertial mass and a dual beat-frequencies laser Doppler interferometer (DB-LDI). In this method, an inertial mass levitated using an aerostatic linear bearing is made to collide with the material being tested at a high initial velocity. During the collision, the velocity of the mass, which is even higher than the critical velocity (±0.56 m/s) defined by the frequency difference of the Zeeman laser, is accurately measured using the DB-LDI. The position, acceleration, and impact force of the mass are calculated from the measured velocity. Using the proposed method, the mechanical properties of a visco-elastic material under a high-speed impact loading condition can be accurately evaluated.

Development of a New Data Processing System for Increasing the Accuracy of a Levitation Mass Method (LMM) based Measurement

“…The acceleration must be accurately measured, so it is measured using optical interferometer. The optical interferometer could not be measure acceleration, but generated from velocity which obtains using principle of Doppler Shifting Frequency [1], [17]- [19].…”