X-ray-based 3D trajectory reconstruction in Car Crash: An assessment within advanced dynamic deformation measurement methods

New challenges in vehicle design and safety testing have emerged. These are primarily driven by the introduction of heavier electric vehicles and altered mass distribution. This necessitates performance across all types of crash tests, particularly lateral impacts, which remain a significant portion of accidents and are challenging due to limited space for energy absorption compared to frontal crashes. This paper presents the methodology and validation of an innovative high-speed displacement measurement technique, along with its implementation and comparison to conventional approaches. A full-scale crash test of a sport utility vehicle (SUV) based on the European New Car Assessment Programme (Euro NCAP) side-impact protocol, is conducted using a deformable mobile barrier launched at 60 km/h. The study focuses on barrier intrusion and driver-side door deformation, with selected structural points tracked throughout the event. Three measurement methods are compared: (i) an advanced experimental approach developed by Fraunhofer EMI, known as X-ray Car Crash (XCC), which combines high-speed X-ray radiography with full-scale crash testing; (ii) a multi-camera 3D Digital Image Correlation (DIC) system; and (iii) a conventional 6-axis accelerometer (ACC) setup used for trajectory reconstruction. Within this framework, the XCC framework is extended to quantitative 3D trajectory tracking using X-ray imaging at 1000 Hz, representing the first full-scale side-impact application with a comprehensive validation of the method. The methods are evaluated and compared in terms of their ability to provide validated, quantitative assessment of vehicle passive safety and internal structural deformation.