04/16/07

Experiment 2: Extreme Vibration Test

Figure 1: Set up of Experiment 2

This experiment subjected the MASM to extreme vibration.  This test will determine if the system as a whole will contribute to additional vibration as a result of the moving parts of the micro-adjustments.  The spring mass damper system will also be under inspection for elimination of vibration.  This test will be conducted at a frequency range of 5 to 15 Hz with a displacement of 0.5 inches in the positive and negative z-direction.  Figure 1 above shows the setup for this experiment.  Accelerometers were used to measure the vibration at various points on the device, their locations are illustrated in Figure 2.  Click on the figure for a description of the accelerometer locations.

Figure 2: Accelerometer locations to measure the vibration.

Click Here for a complete description of the apparatus used and procedures followed for this test.

Experiment 2 Results

Figure 3

Figure 4

Figure 5

Figures 3-5 above show output plots of the vibration test.  Figure 3 illustrates the acceleration against the frequency, figure 4 shows the velocity against the frequency, and figure 5 displays the displacement of the system against the frequency.

The MASM was designed to dampen the small amount of vibration that it would receive if placed in the VCCT.  The amount of vibration that it experienced in this particular experiment was unrealistic, yet the results were very promising.  If you compare the data from accelerometers 2 and 4 (yellow is the ceiling and white is the projector) it can be seen that throughout the frequency range of 5 to 15 Hz, the vibration amplitude is lower at the projector than at the input of the ceiling.  This is especially evident from the range of 7 to 8 Hz, where there is as much as a 50% reduction in amplitude.  All three plots (figures 3-5) show similar results, suggesting that the system is working to varying degrees throughout the frequency spectrum.