Popis: |
This paper presents two new mechanical methods in the stroboscopic holographic vibration analysis. In one of the two, the oscillating mirror of the electromagnetic oscillograph is used, and in another, the pulse-motor is used. The mirror oscillating sinusoidally reflects the laser beam and the vibrated laser beam is strobed by the slit. The pulse-motor rotates by the constant angle when one pulse is given and the laser beam is strobed by the slits attached to the motor. As the oscillating mirror and the pulse-motor are driven by the signal that is the input to the vibrator of the subject, or the transformed one, it is easy to synchronize the strobing to the vibration of the subject and the strobing can be synchronized to the signal detected from the vibration of the subject. Particularly, the method using the oscillating mirror is easy, cheap and one of the mechanical methods that can be used in the highest frequency. The vibration patterns of the circular plate clamped at the center and the loudspeaker are got by those methods. |