Sonic IR is an emerging NDE technique being developed at the Wayne State University that has potential crack detectability both in metallic and non-metallic materials. The technique has applications in various sectors of NDE including aerospace, automotive, transportation, pressure vessel, and piping and manufacturing. Although it is established that friction caused by rubbing between the faying surfaces (i.e. tightly closed surfaces of closed surface cracks) or other material flaws under sonic load generates heat, the relationship of the quality and quantity of heat generation mechanics are not yet well known. In this paper a simple aluminum plate sample with generated cracks is studied through both experimentation and finite element (FE) modeling and simulation. The dynamics of Sonic IR for a simple metallic sample are analyzed with LS-DYNA3D finite element program. The FE analysis does support the frictional heat generation due to the rubbing of the faying surfaces of the crack faces. FE analysis also allows visualization of crack faces rubbing mode. The experiments show the infrared signal level as the indication of heat generation, captured in real time video frames. In FE simulation the energy plot at the crack interface is an indicator of heat generation and the energy plots are compared with the infrared signal plot. The results of varying test parameters in experiments as well as FE simulations are also discussed.
Relationship between Heat Generation at Single Edge Penetrating Crack in Strip Specimen and Vibrational Modes of Specimen in Sonic-IR Method
