A Feasibility Study for a Nonlinear Guided Wave Mixing Technique

Abstract

Ultrasonic non-destructive testing is an effective means of examining objects without destroying them. Among such testing, ultrasonic nonlinear evaluation is used to detect micro-damage, such as corrosion or plastic deformation. In terms of micro-damage evaluation, the data that comes from amplitude comparison in the frequency domain plays a significant role. Its technique and parameter are called ultrasonic nonlinear technique and nonlinearity. A certain portion of nonlinearity comes from the equipment system, while the other portion of nonlinearity comes from the material. The former is system nonlinearity, while the latter is material nonlinearity. System nonlinearity interferes with interpretation, because its source is not from the material. In this study, in order to minimize system effects, a mixing technique is implemented. To use the large area inspection ability of the guided wave, the main research issue in this paper is focused on the guided wave mixing technique. Moreover, several bulk wave mixing theory equations become good concepts for guided wave mixing theoretical study, and the conventional nonlinear technique and guided wave mixing experimental results are compared in this study to confirm the reliability. This technique can play an important role in quantitatively discriminating fine damage by minimizing the nonlinearity of the equipment system.

Ultrasonic Nonlinearity Experiment due to Plastic Deformation of Aluminum Plate Due to Bending Damage

“…Additionally, researchers are exploring methods to enhance sensitivity by mitigating system nonlinearity [ 24 ], as well as investigating the effects of thermal aging on sensitivity [ 24 ]. However, it is important to note that these studies primarily focus on micro-damage assessment during the material’s initial manufacturing process and intrinsic properties [ 25 , 26 , 27 ]. Currently, there is a lack of experimental verification regarding material deformation under conditions such as tension or compression due to bending.…”