Measurement of dynamic fracture toughness and failure behavior for explosive mock materials

Abstract

In this work, a pre-cracked semi-circular shaped explosive simulant was loaded using a split Hopkinson pressure bar (SHPB). A high-speed camera was used to capture the deformation and fracture process of the specimen in situ. The digital images were processed using the digital image correlation (DIC) method. Next, full displacement and strain fields were obtained. The displacement vector field shows that the specimen fractured under tensile stress action. The strain field can be used to predict the crack propagation. Results show that the method of combined DIC and SHPB is effective to study the dynamic deformation and fracture behavior of explosive simulants. In addition, the specimen was loaded using a drop weight. The fracture toughness of the specimen was preliminary measured.

Keywords

digital image correlation / polymer bonded explosive simulant / split Hopkinson pressure bar (SHPB) / semicircular bending test / deformation / fracture toughness

References

[1] Palmer S J P, Field J E, Huntley J M. Deformation, strengths and strains of failure of polymer bonded explosives. Proceedings of the Royal Society of London. Series A, 1993, 440(1909): 399–419

[2] Chen P, Huang F, Ding Y. Microstructure, deformation and failure of polymer bonded explosives. Journal of Materials Science, 2007, 42(13): 5272–5280

[3] Chen P, Xie H, Huang F, Huang T, Ding YDeformation and failure of polymer bonded explosives under diametric compression test. Polymer Testing, 2006, 25(3): 333–341

[4] Wen M, Ma L, Tian Y.. Experimental study on the plane strain fracture toughness of high polymer bonded explosive. Journal of Explosives and Propellants, 2001, 2: 16–21

[5] Pan B, Qian K M, Xie H M, Asundi A. Two-dimensional digital image correlation for in-plane displacement and strain measurement: a review. Measurement Science & Technology, 2009, 20(6): 062001–062007

[6] Rae P J, Goldrein H T, Palmer S J P, Field J E, Lewis A L. Studies of the failure mechanisms of polymer bonded explosives by high resolution moiré interferometry and environmental scanning electron microscopy. In: Proceedings of 11th International Detonation Symposium, 1998, 66–75

[7] Rae P J, Palmer S J P, Goldrein H T, Lewis A L, Field J E. White light digital image cross-correlation analysis of the deformation of composite materials with random microstructure. Optics and Lasers in Engineering, 2004, 41(4): 635–648

[8] Rae P J, Goldrein H T, Palmer S J P, Field J E. The use of digital image cross-correlation to study the mechanical properties of a polymer bonded explosive. In: Proceedings of 12th International Detonation Symposium, 2002

[9] Li M, Zhang J, Xiong C Y, Fang J, Mli J, Hao Y. Damage and fracture prediction of plastic bonded explosive by digital image correlation processing. Optics and Lasers in Engineering, 2005, 43(8): 856–868

[10] Liu Z W, Xie H M, Li K X, Chen P W, Huang F L. Fracture behavior of PBX simulant subject to combined thermal and mechanical loads. Polymer Testing, 2009, 28(6): 627–635

[11] Chong K P, Kuruppu M D. New specimen for fracture toughness determination for rock and other materials. International Journal of Fracture, 198 4, 26: 59–62

[12] Zhou Z, Chen P, Huang F. Experimental study on the micro/macro fracture behavior of PBX using digital speckle correlation method. Chinese Journal of High Pressure Physics, 2011, 25(1): 1–7 (in Chinese)

[13] Luo J R, Chen Y Z, He P, Yu Z S, Guo W G. Effects on material dynamic initiation toughness. Key Engineering Materials, 1998, 145-149: 279–284

Acknowledgments

The work was supported by the National Natural Science Foundation of China (Grant No. 10832003) and the Program for New Century Excellent Talents (No. NCET-06-0159). The authors thank Prof. Nie Fude from the Institute of Chemical Materials, Chinese Physical Academy, for providing the PBX simulant. The authors also thank Prof. Yao Xuefeng from Tsinghua University for instructing the drop-weight test.

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg