The effects of laser parameters on the excitation of laser-generated surface acoustic waves in the Q345 steel

Abstract

Nondestructive testing plays an important role in modern cities. Laser-generated surface acoustic waves (SAWs) are widely used in the nondestructive testing of structures due to their advantages, such as being non-contact and having a wide frequency bandwidth, long distance propagation, little attenuation, and so on. Q345 steel is currently used in many areas, especially in large structures. In order to utilize laser-generated SAWs more reasonably, this paper discusses the effects of laser parameters on the excitation of SAWs in Q345 steel with the numerical method. The three parameters of the pulse energy, rise time, and pulse width are discussed separately. The results show that the amplitude of displacement is directly proportional to the pulse energy and inversely proportional to the rise time and pulse width. These proposed results can provide a guideline for the choice of the excitation parameters in the laser-generated SAWs nondestructive evaluation on Q345 steel.