Quantum mechanics

Control (management)

Chaotic

Engineering

Ultrasonic sensor

Computer science

Acoustics

Physics

Nonlinear system

Trajectory

Van der Pol oscillator

Image (mathematics)

Lyapunov exponent

Electronic engineering

Artificial intelligence

Sensitivity (control systems)

Control theory (sociology)

Noise (video)

Ultrasonic testing

International Journal of Pressure Vessels and Piping

The sensitivity of small defect detection and the location of small defect in pipes are the main difficulties of the present ultrasonic guided wave inspection technology. A Van der Pol (VdP) chaotic system's sensitivity to initial conditions and capability of being immune to noise was used to establish the relationship between local defect positions and chaos damage factors in this paper. Simulation studies of phase trajectory and Lyapunov exponents based on damping ratio detection of a Van der Pol system were performed. Five kinds of oblique defects with inclined angles of 0°, 30°, 45°, 60°, and 90° were investigated by experiment and analyzed using the location method of a Van der Pol chaotic system. Both the simulated and experimental results show that the proposed method could be used to inspect weaker guided waves and locate tiny defects.

Defect detection in pipes using Van der Pol systems based on ultrasonic guided wave