Analysis for propagation characteristics of longitudinal mode and torsional mode guided waves in rod
Regarding the application of guided waves in one-dimensional structure, the propagation characteristics of the longitudinal guided wave and torsional guided wave are investigated. The dispersion equations of guided wave in the longitudinal and torsional modes in one-dimensional component are derived. Through programming numerical calculation in MATLAB, the frequency dispersion curves of the two modes are obtained, which imply that the engineering application of guided waves in detection of rod needs to choose an appropriate frequency and the corresponding propagation characteristics of the waves should be combined to get reliable results. The dispersion characteristics analysis results in different radius of rods show that it is feasible for detecting the defects in rod using L(0,1) mode of ultrasonic guided waves.
Excitation and Reception of Ultrasonic Guided Waves Using PZT Transducers
PZT transducers have been used to excite and receive ultrasonic guided waves in steel pipes. The reflect and transmission rules of guided waves are researched. The results are shown that ultrasonic guided waves can be generated by angle probe and can be used to inspect the flaws in the pipes. Here the non-flaw pipe and the pipe with artificial flaws are inspected respectively. The ultrasonic beam wraps around the inspected pipe and the maximum reflection signals are obtained when the angle probe deviates from the straight line where the. flaws are.
Finite Difference Modeling on the Temperature Field of Substrate in Friction Surfacing
Friction surfacing is an advanced process of great potential, especially in the field of repair and reclamation of worn and damaged components. As a kind of thermal processing technology, the temperature profile and changes of the substrate in friction surfacing are important factors to get coatings of high quality. In this paper, the temperature field of the substrate during the process is simulated by finite difference method. The results are consistent with experiments, reappearing the temperature change of the substrate during friction surfacing, allowing further study on figuration and quality of coatings.