Integrated Optical Deformation Measurement with TIR Prism Rods

Area of Science:

• Optical Measurement
• Mechanical Engineering
• Materials Science

Background:

• Accurate measurement of material deformation, particularly torsion, is crucial for structural integrity and condition monitoring.
• Existing methods may have limitations in sensitivity, adaptability, or integration into machine elements.

Purpose of the Study:

• To introduce a novel optical measurement principle for detecting deformation, with a focus on torsion.
• To demonstrate the system's sensitivity and potential for analyzing combined load cases.
• To explore the integration of this principle into machine elements for real-time condition monitoring.

Main Methods:

• Utilizing a laser beam guided via total internal reflection (TIR) within a prism rod.
• Measuring changes in the laser beam's path caused by reflections within the rod.
• Analyzing the effect of these path changes on the outcoupling position of the laser to quantify torsion.

Main Results:

• The system achieves high torsion sensitivities, ranging from 350 µm/° to over 7000 µm/°, depending on the torsion angle.
• Sensitivity significantly exceeds a defined decency level, by approximately a factor of 55 at zero torsion.
• The principle can be adapted for different load cases, and dual-laser systems can distinguish bending and torsion.

Conclusions:

• The TIR prism rod principle offers a highly sensitive method for measuring torsion and other deformations.
• The system's adaptability and potential for integration into machine elements enable effective condition monitoring of mechanically loaded components.
• This optical measurement technique provides a promising approach for advanced structural health monitoring and performance analysis.