Stress Measurement of a Pressurized Vessel Using Ultrasonic Subsurface Longitudinal Wave With 1-3 Composite...

Area of Science:

• Materials Science
• Mechanical Engineering
• Non-Destructive Testing

Background:

• Ultrasonic subsurface longitudinal (SSL) waves are used for stress sensing in pressurized vessels.
• Excitation of SSL waves using predefined functions with composite transducers requires further investigation.

Purpose of the Study:

• To develop an advanced stress-sensing method for pressurized vessels using 1-3 composite transducers.
• To enhance SSL wave signal intensity and sensor accuracy through specific waveform excitation.

Main Methods:

• Utilized composite-type transducers with wide frequency bandwidth (>60%) and predominant thickness mode.
• Employed a specific toneburst waveform for SSL wave excitation and detection.
• Conducted finite element analysis and pulse-echo tests to validate transducer performance.
• Applied principal component regression (PCR) for stress sensing under varying temperatures.

Main Results:

• Composite-type transducer signal intensity was up to 45.3% higher than single-phase transducers.
• Developed transducer exhibited a frequency bandwidth of 60.7%, suitable for Hanning-windowed toneburst signals.
• A linear relationship (0.335 ns/MPa) was observed between SSL wave time delay and pressurized vessel stress.
• PCR model demonstrated significantly lower error (0.62 MPa) compared to least squares regression (9.49 MPa).

Conclusions:

• The developed composite transducer and toneburst waveform method effectively enhances SSL wave signal intensity and accuracy for stress sensing.
• The study confirms a reliable linear correlation between SSL wave time delay and mechanical stress in pressurized vessels.
• Principal component regression offers a robust and accurate approach for stress sensing, especially under varying temperature conditions.