Influence of Change in Inner Layer Thickness of Composite Circular Tube on Second-Harmonic Generation by Primary Circumferential Ultrasonic Guided Wave Propagation
Ming-Liang Li1, Ming-Xi Deng1**, Guang-Jian Gao1, Han Chen1, Yan-Xun Xiang2**
1Department of Physics, Logistics Engineering University, Chongqing 401331 2School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237
Abstract：The influence of change in inner layer thickness of a composite circular tube is investigated on second-harmonic generation (SHG) by primary circumferential ultrasonic guided wave (CUGW) propagation. Within a second-order perturbation approximation, the nonlinear effect of primary CUGW propagation is treated as a second-order perturbation to its linear response. It is found that change in inner layer thickness of the composite circular tube will influence the efficiency of SHG by primary CUGW propagation in several aspects. In particular, with change in inner layer thickness, the phase velocity matching condition that is originally satisfied for the primary and double-frequency CUGW mode pair selected may no longer be satisfied. This will remarkably influence the efficiency of SHG by primary CUGW propagation. Theoretical analyses and numerical results show that the effect of SHG by primary CUGW propagation is very sensitive to change in inner layer thickness, and it can be used to accurately monitor a minor change in inner layer thickness of the composite circular tube.
2017, Vol. 34 
