IntroductionLG comprises of two layers of glass and one or more layers of polymer film (inter-layer) that is sandwiched in-between by putting under heat and pressure. Inter-layer improves mechanical properties like impact strength, fracture toughness and failure mode of LG [1]. As area of impact increases there is possibility of increment of the impact resistance. The fracture of LG is designed so as to the Inter layer keeps together broken pieces that can possibly cause dangerous incidents or accidents. The LG dampens the energy of impact and improves the brittle fracture behavior when compared with monolithic glass. This functionality forces designers to use LG wherever there may be an injury risk due to glass fracture. A good no of theoretical studies [2][3][4][5][6][7][8], experimental studies [9][10][11][12][13][14][15][16][17][18][19][20][21][22] numerical studies [10,, LS DYNA and ABAQUS based studies [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] and discrete element (DE)/finite element (FE) based studies are reported to analyze impact failure of LG. The present work is focused on reviewing the numerical algorithms used to model the impact fracture of LG.
Literature ReviewImpact failure analysis of LG is commonly done experimentally followed by numerical simulations. The failure processes of LG due to impact analyzed during pre-failure, failure and post-failure stages. Analytical models are commonly employed to describe the mechanical performance of LG for the pre and post-failure stages [46][47][48][49][50]. The post-failure response of LG is also explained by numerical simulations [51,52] and experiments. The literature frequently focuses on the principal damage pattern and glass-ply cracking. The commonly used numerical algorithms sighted in the literature for impact simulation are element deletion method (EDM), the continuum damage mechanics (CDM), the discrete element method (DEM), the combined discrete/finite element methods (DEM/FEMs), the extended finite element method (XFEM) and the cohesive zone model (CZM). The adhesion modeling is usually simulated using shared node method, the penalty-based methods and the intrinsic CZM. The EDM consist of removal of the mass of elements from the global mass matrix or set the stress of elements to zero, so as to represent the failure of these elements (used in LS-DYNA). This method is used in [53,54]. Xu et al. developed a numerical model on LG-PVB subjected to low-speed impact. The LG was impacted by a standard head form impactor at the speed of 8 m/s based on the LS-DYNA platform. The results were compared with the dynamic experiments of LG-PVB under head form impact to find the most accurate FE model [55]. Pyttel et al. [56] have found failure benchmark norm for the LG when subjected to impact loading. It has been stated that a hazardous energy threshold should be reached during a finite expanse before failure took place. To regulate the norm and estimate its precision, various tests with curved and plain samples of LG were p...