Experimental study of ultrasonic beam sectors for energy conversion into Lamb waves and Rayleigh waves.
When a bounded beam is incident on an immersed plate Lamb waves or Rayleigh waves can be generated. Because the amplitude of a bounded beam is not constant along its wave front, a specific beam profile is formed that influences the local efficiency of energy conversion of incident sound into Lamb waves or Rayleigh waves. Understanding this phenomenon is important for ultrasonic immersion experiments of objects because the quality of such experiments highly depends on the amount of energy transmitted into the object. This paper shows by means of experiments based on monochromatic Schlieren photography that the area within the bounded beam responsible for Lamb wave generation differs from that responsible for Rayleigh wave generation. Furthermore it provides experimental verification of an earlier numerical study concerning Rayleigh wave generation.
Georgia Institute of Technology, UMI Georgia Tech - CNRS 2958, George W. Woodruff School of Mechanical Engineering, Georgia Tech Lorraine, Laboratory for Ultrasonic Nondestructive Evaluation, 2 rue Marconi, 57070 Metz, France. Electronic address: declercqdepatin@gatech.edu.
Nico Felicien
NF
Declercq
D003198:Computer Simulation; D004735:Energy Transfer; D019220:High-Energy Shock Waves; D008962:Models, Theoretical; D012542:Scattering, Radiation
Bounded beams; Lamb waves; Mode conversion; Rayleigh waves; Schoch effect