چكيده به لاتين
In this thesis, experimental and numerical investigation of foreign object impact to the windshield has been carried out. Automotive windshield is recognized as a 3 layer glass/PVB/glass composite. Although glass layers’ behavior is dominant in small deformations of windshield, in large deformations (such as foreign object impact) PVB plays a significant role due to failure of glass layers. As a consequence, investigation of failure behavior is essential in determining the composite mechanical behavior. At experimental investigation of this thesis, lab-sized specimens were provided from Jeep car windshield and tested in drop tower system at low velocity impacts. Numerical simulations of low velocity impacts were carried out in commercial ABAQUS software. For accurate prediction of windshield behavior in impact loading, brittle cracking damage model was applied in FEM simulation. Comparison of Numerical and experimental results verifies the Finite Element model for modeling the low velocity impact to the windshield (3 layers laminated glass). Furthermore, low velocity impact problem was simulated for a complete windshield. Effects of PVB thickness, pedestrian’s head impact velocity and impact position on mechanical behavior of windshield and also resultant acceleration of the head have been examined. The results showed that applying the damage effects in glass layers have a significant role in final behavior of the structure. According to the FEM simulations, head impact to the borders of the windshield is more dangerous than the central impacts, so that HIC value can exceed more than 2 times. In addition, although increasing the PVB thickness, intensifies the maximum resultant force value, the reported optimized PVB thickness for central impacts in literature does not apply for lateral impacts.
