Efficient simulation of acoustic emission with reflections removal based on infinite element and Rayleigh damping

Acoustic Emission (AE) is defined as the transient elastic wave generation due to a rapid release of strain energy within or on the surface of a structure, which is well known as a sensitive technique to detect various types of damage, such as crack propagation in structure. This paper presents a new simulation method for AE by investigating the removal of unwanted reflections in the waveguides including plate and thin-walled cylinder structures which is based on the theory of the infinite element and Rayleigh damping. The finite element (FE) models are established with reflections removal condition proposed in this paper. The properties of AE source mechanism, propagation and reflection are investigated through finite element (FEM). To validate accuracy of the FE technique, the AE simulation of an isotropic plate and the pencil lead broken test on a steel plate are carried out, and the data is processed by the Choi-Williams transformation. It manifests that the simulation results are in good coincide with the experiment results. Then the removal effect is investigated by AE simulations in a thin-walled cylinder and an anisotropic plate. All of the results demonstrate that the Rayleigh damping has significant influence on the removal effect of infinite elements. Moreover, illustrate that high accuracy removal of unwanted reflection can be realized by the infinite elements with appropriate Rayleigh damping.