Research on the mechanical performance of windshield glass for rail vehicles under gravel impact loadings

Abstract

This study aims to experimentally and numerically explore the bearing capacity of windshield glass for rail vehicles under projectile impact by gravel along the railway. The gravel particle sizes, ranging from 0.5 to 10 mm, were divided into 7 levels, and two conditions were chosen based on loading angles: 90° vertical impact and 45° oblique impact. Multiple gravel impacts were conducted based on the conversion of wind-blown sand flow intensity, analysing the difference in fracture velocity of windshield glass compared with single gravel impact. Finally, a stable 4 kPa wind pressure was applied to the windshield glass, and simultaneous gravel impact was performed. By comparing the impact test results without wind pressure, the weakening effect of wind pressure load on the impact resistance of windshield glass was analysed. Lastly, the dynamic process of projectile penetration and fracture of windshield glass was numerically simulated. This involved studying the crack propagation process and analysing the fracture velocity of windshield glass under projectiles made of different materials. By comparing the simulation and experimental results, the accuracy and reliability of this study were verified. The research results show that the larger the gravel particle size, the lower the chip and fracture velocities of the windshield glass. The chip velocity and fracture velocity of windshield glass under single gravel oblique impact at 45° are higher than those under vertical impact conditions, approximately 1.2 times and 1.13 times higher, respectively. Moreover, the fracture velocities under 3 and 6 gravel impacts are approximately 12 % and 20 % lower, respectively, compared to single gravel impact condition. Additionally, stress oscillations were observed to occur due to the cyclic process of stress accumulation, energy release through crack propagation, stress decline, and further stress accumulation. This was observed by tracking the stress state near the crack tip of the windshield glass.

Keywords

• Mechanical performance
• Windshield glass of rail vehicle
• Sand and gravel impact
• Wind pressure
• Oblique and vertical impact