ABSTRACT
Laminated glass is extensively used in automotive windshields, making it crucial to have a comprehensive understanding of its fracture mechanism to ensure driver and pedestrian safety in various windshield impact scenarios. Current research on the cohesive zone model of glass impact failure has encountered challenges related to accuracy and computational efficiency. This paper addresses these issues by utilizing the finite element software LS-DYNA, which integrates a cohesive zone model and thick shell (Tshell) elements to simulate and analyze the impact failure process of laminated glass. The combination of Tshell and cohesive elements was validated using a DCB example. Subsequently, the proposed method was applied to simulate the impact damage on an automobile's front windshield, providing valuable insights from the obtained results. Finally, the influence of curvature, the number of layers, and the thickness ratio of each layer were investigated, leading to some valuable conclusions. Firstly, an increase in the thickness of the upper glass layer correlates with a decrease in the peak acceleration of the dummy-head model due to the ductility of PVB material. Secondly, when a curvature exists, the arched configuration of the windshield promotes higher resistance against impact, consequently leading to increased peak acceleration.
ABSTRACT
Interlaminar failure caused by scratches is a common damage mode in automotive coatings and is considered the potential trigger for irreversible destruction, i.e., plowing. This work strives to numerically investigate the mechanisms responsible for the complex scratch behavior of an automotive coating system, considering the interfacial failure. A finite element model is developed by incorporating a large deformation cohesive zone model for scratch-induced debonding simulation, where the mass scaling technique is utilized to minimize computational burden while ensuring accuracy. The delamination phenomenon of the automotive coating is reproduced, and its effects on scratch damage behavior are analyzed. Accordingly, it is revealed that the interlaminar delamination would produce significant stress redistribution, which leads to brittle and ductile damage of the coating and consequently affects the formation of plowing. Eventually, parametric studies on the effects of interfacial properties are performed. They demonstrate that the shear strength and shear fracture energy dominate scratch-induced delamination.
