Effect of Lateral Deviation on Braking Dynamics of Automotive Brake Discs

The advancement of the automotive industry and its associated challenges necessitate the application of modern diagnostic methods for fault detection and the prevention of potential failures. The aim of this scientific publication is to investigate the braking behavior of brake discs subjected to varying degrees of lateral deviation, using noise, vibration, and harshness (NVH) diagnostic methods. The research aims to support the development and broader adop-tion of advanced, autonomous maintenance procedures. During the experimental program, a seventh-generation electric Volkswagen e-Golf brake disc was tested under both laboratory and real-world proving ground conditions. The results of the analysis show that as the brake disc run-out increased, lateral acceleration values intensified (pulsation was observed); these vibra-tions were clearly perceptible through the steering wheel during testing. Based on the acquired data, the differences in braking dynamics were analysed. Using the applied NVH method, along with the selected measurement points, provided a reliable diagnostic procedure. The findings support preventive maintenance and improved design reliability. Quantitatively, increasing disc run-out from 0.02 mm (OEM) to 0.12 mm (defective aftermarket) raised lateral acceleration peaks at the wheel carrier from within ±1 g to nearly ±3 g and lengthened the average braking distance from 39 m to 41.5 m at 100 km/h (n=3 per disc). These findings indicate a measurable safety impact under otherwise identical conditions.