Abstract
In this paper, fracturing in coal under impact loads was studied using experimental and numerical approaches. Three-point beam bending tests were carried out on coal samples under impact loads. During the testing, cracking velocity in the samples was captured using a multi-spark high-speed photography system. Characteristics of the fracture surface were investigated using the scanning electron microscopy, 3D laser surface topography scanner and X-ray micro Computed Tomography (X-ray micro-CT). Differences between the fracture surface under impact loads and that in quasi-static test were analysed. Moreover, discrete numerical modelling was conducted to assess the influence of impact velocity, heterogeneity, and grain size on dynamic fracturing in coal. Based on observations from the testing and numerical simulation, it was concluded that the influence of heterogeneity and grain size was more pronounced in dynamic fracturing comparing to that under quasi-static loading.
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Acknowledgments
The research is financially supported by the Major State Basic Research Development Program Fund (Grant No. 2010CB226804, 2010CB226801), National Natural Science Foundation of China (Grant No. 51174213), New Century Excellent Talents in Ministry of Education Support Program of China (No. NCET-10-0775), Australian Research Council (No. DE130100457), State Key Lab of Coal Resources and safe Mining (No. SKLCRSM11KFA02), State Key Lab for Geomechanics and Deep Underground Engineering (No. SKLGDUEK1021) and Fundamental Research Funds for the Central Universities. The authors specially thank Dr. Zhu Jie and Dr. Lv Yukai for their help in the experiments. The authors thank the anonymous reviewer for the valuable comments and helpful suggestions.
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Zhao, Y., Zhao, GF. & Jiang, Y. Experimental and numerical modelling investigation on fracturing in coal under impact loads. Int J Fract 183, 63–80 (2013). https://doi.org/10.1007/s10704-013-9876-6
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DOI: https://doi.org/10.1007/s10704-013-9876-6