Calibration of a 3D-FE Model with Non-Contact Laser Doppler Vibrometer (LDV) Measurements of Pavement Deflection Velocity Under Accelerated Pavement Testing

This research utilizes Laser Doppler Vibrometer (LDV) technology to measure pavement deflection velocity under heavy moving loads at the Virginia DOT Accelerated Pavement Testing (VDOT APT) facility. While LDVs are typically integrated into Traffic Speed Deflectometers (TSDs) for measuring deflection velocities, this research employs a standalone, tripod-mounted LDV to capture highly repeatable data under controlled Heavy Vehicle Simulator (HVS) loading. A three-dimensional viscoelastic finite element (3D-FE) model was developed in Abaqus (version 2016) and calibrated using the LDV-measured deflection velocities and site-specific material properties. The model incorporates asphalt viscoelasticity, three-dimensional nonlinear contact stresses, and continuous loading conditions. Results demonstrate very good agreement between the calibrated 3D-FE model and observed responses, with calculated percentage differences of 0.6% and 3.4% for the maximum and minimum deflection velocity peaks, respectively. These findings, along with a 10% ratio between the standard deviation of the error and the measured signal, validate the model’s accuracy and the effectiveness of LDV instrumentation. This stand-alone application of a TSD-type LDV at an APT facility, to directly measure pavement deflection velocity under a moving load to calibrate a 3D-FE model, represents a key innovative aspect and addresses an identified gap in the literature on LDV-based pavement evaluation techniques. It should be noted that the proposed framework is calibrated for a single pavement structure under controlled loading and environmental conditions, and is applicable to the initial, undamaged state of the pavement. Further validation across different material configurations, environmental gradients, and damage stages is required to generalize the approach.