Numerical Simulation of Damage in Pile for Health Monitoring Using 3D-FEA

Internal damage in deep foundation piles can critically alter their structural integrity and dynamic response, making early and accurate detection essential for ensuring long-term performance and safety. This study presents a three-dimensional finite element modeling (3D-FEA) framework to evaluate the sensitivity of dynamic responses to internal damage under high-strain impact loading. A slender cylindrical pile (L/d = 45) embedded in a layered soil medium is analyzed, with damage simulated as a mid-height circular notch using two different modeling approaches: interface elements with reduced strength, and solid volume elements with degraded stiffness. The time-domain analysis involves applying an impact load at the pile head and recording displacement and velocity responses at multiple depths. Results reveal that the interface-based damage model fails to generate distinguishable reflections from the damaged region, limiting its diagnostic capability. In contrast, the volume-element model successfully captures wave scattering, amplitude attenuation, and early reflection signatures, enabling clear differentiation between damaged and undamaged conditions. The findings underscore the importance of refined damage zone representation for realistic and reliable pile integrity evaluation.