Bending wave propagation in rotating objects measured by pulsed TV holography

Area of Science:

• Mechanical Engineering
• Optical Metrology

Background:

• Rotating disks are susceptible to transient bending waves.
• Accurate measurement of these waves is crucial for understanding disk dynamics and preventing failure.

Purpose of the Study:

• To present a novel, all-electronic method for measuring transient bending waves in rotating hard disks.
• To demonstrate the effectiveness of pulsed TV holography for this application.

Main Methods:

• Utilized pulsed TV holography for non-contact measurement of wave propagation.
• Developed an interference phase evaluation method to compensate for speckle motion caused by disk rotation.
• Employed an all-electronic system, eliminating the need for mechanical image derotators.

Main Results:

• Successfully measured transient bending waves in a rotating hard disk.
• Demonstrated effective compensation for rotation-induced speckle motion.
• Validated the feasibility of an all-electronic, derotator-free measurement technique.

Conclusions:

• Pulsed TV holography offers a viable and efficient method for analyzing dynamic phenomena in rotating systems.
• The developed compensation technique overcomes a key challenge in optical metrology of rotating objects.
• This approach simplifies experimental setups and enhances measurement accuracy for rotating disk dynamics.