Scattering characteristics of vertically incident SH-waves in defective railway components

Common defects in railway track structures, such as cracks and debonding, alter wave propagation paths induced by wheel-rail excitation within the track components. These alterations lead to non-uniform stress distribution, ultimately resulting in defect expansion and a reduced service life of the structure. To address these engineering challenges, core issues were identified, focusing on the propagation and corresponding field distribution of vertically incident SH waves in media containing pores. A wave field model around a circular pore was established based on elastic wave theory. The conformal mapping method was then introduced to associate the wave propagation in an elliptical pore region with the circular pore model. Scattering energy and dynamic stress concentration were employed as local field variables to analyze wave propagation. Results indicate that an increase of the incident wave number aggravates wave scattering, causing the scattering energy distribution around the pore to oscillate. As the pore opening decreases, energy scattering near the wave incident axis becomes more pronounced, intensifying dynamic stress concentration at the pore tips. Furthermore, the influence of inclusions on wave propagation in the pores was explored. It indicates that the transmission effect of inclusions can mitigate energy scattering around the pore. Weaker inclusions and increasing wave numbers were more likely to cause the dynamic stress concentration distribution to exhibit an oscillatory pattern. The characteristics of wave field distribution and the influence of various factors provide a theoretical basis for life prediction and damage detection in railway track structures.