[1] [1] Strassburger E. Ballistic testing of transparent armour ceramics [J]. J Eur Ceram Soc, 2009, 29(2): 267-273.

[2] [2] Patel P, Gilde G, Dehmer P, et al.. Transparent armor [J]. AMPTIAC Quarterly, 2000, 4(3): 1-6.

[3] [3] Iwamoto S, Nakagatio A N, Yano H, et al.. Optically transparent composites reinforced with plant fiber-based nanofibers [J]. Appl Phys A, 2005, 81(6): 1109-1112.

[4] [4] J K Sinha, H V Tippur, L M Xu. An interferometric and finite element investigation of interfacial crack tip fields: role of mode-mixity on 3-D stress variations [J]. Int J Solids Struct, 1997, 34(6): 741-754.

[5] [5] Arakawa K, Mada T, Takahashi K. Experimental analysis of dynamic effects in brittle fracture of PMMA [J]. Key Engineering Materials, 2000, 183-187: 265-270.

[6] [6] Dally J W, Barker D B. Dynamic measurements of initiation toughness at high loading rates [J]. Exp Mech, 1988, 28(3): 298-303.

[7] [7] Bless S, Chen T. Impact damage in layered glass [J]. Int J Fract, 2010, 162(1-2): 151-158.

[8] [8] Subhash G, Haney EJ. Analysis of interacting cracks due to sequential indentations on sapphire [J]. Acta Mater, 2011, 59(9): 3528-3536.

[9] [9] W Xu, X F Yao, M Q Xu. Fracture characterizations of V-notch tip in PMMA polymer material [J]. Polymer Testing, 2004, 23(5): 509-515.

[10] [10] X F Yao, T C Xiong, W Xu. Experimental investigations on deformation and fracture behavior of glass sphere filled epoxy functionally graded materials [J]. Appl Composite Mater, 2006, 13(6): 407-420.

[11] [11] W Xu, X F Yao, M Q Xu. Fracture investigation of PMMA specimen using coherent gradient sensing (CGS) technology [J]. Int J Solids and Structures, 2006, 43(5): 1189-1200.

[12] [12] Periasamy C, Tippur H V. A full-field digital gradient sensing method for evaluating stress gradients in transparent solids [J]. Appl Opt, 2012, 51(12): 2088-2097.

[13] [13] Periasamy C, Tippur H V. Measurement of crack-tip and punch-tip transient deformations and stress intensity factors using digital gradient sensing technique [J]. Eng Fract Mech, 2013, 98: 185-199.

[14] [14] Hareesh V Tippur, Sridhar Krishnaswamy, Ares J Rosakis. Optical mapping of crack tip deformations using the methods of transmission and reflection coherent gradient sensing: a study ofcrack tip K-dominance [J]. Int J Fract, 1991, 52(2): 91-117.

[15] [15] McNeill S R, Peters W H, Sutton M A. Estimation of stress intensity factor by digital image correlation [J]. Eng Fract Mech, 1987, 28(1): 101-112.

[16] [16] S Yoneyama, T Ogawab, Y Kobayashib. Evaluating mixed-mode stress intensity factors from full-field displacement fields obtained by optical methods [J]. Eng Fract Mech, 2007, 74(9): 1399-1421.

[17] [17] Sanford R J. Application of the least-squares method to photoelastic analysis [J]. Exp Mech, 1980, 20(6): 192-197.

[18] [18] A J Rosakis, K Ravi-Chandra. On Crack Tip Stress States and Experimental Evaluation of Three-Dimensional Effects [R]. Pasadena: California Institute of Technology Report FM-84-2, 1984.

[19] [19] Janssen M, Zuidema J, Wanhill R J H. Fracture Mechanics (2nd ed.) [M]. London: Spon Press, 2006.