摘要为综合研究花岗岩细观特征和层裂断口微观特征，利用霍普金森杆装置对花岗岩杆件进行不同冲击荷载的层裂试验，通过晶体矿物学研究矿物细观结构，利用高速摄影仪研究细观裂纹扩展，采用能谱仪(energy dispersive spectrometer，EDS)和扫描电镜(scanning electron microscopy，SEM)研究试样层裂断口面微观结构，最后运用分形原理，定量计算层裂断口的粗糙度。试验结果表明：花岗岩的矿物细观结构对层裂破坏具有重要影响，其中，长石、石英、云母作为花岗岩的主要成分，表现尤为突出；同时，这些矿物的分布也影响着细观裂纹的扩展。EDS和SEM图片的微观分析表明不同矿物具有不同的微观断裂特征，断口整体上的破碎程度和粗糙度，都有随着冲击荷载增大而增大的趋势，这种趋势在分形维数值的结果分析中得到了验证。
Abstract：To comprehensively research the characteristics of mesoscopic minerals and microscopic fractures of granite，the split Hopkinson bar(SHPB) device was employed to perform the spalling experiments of granite rods under different impact loads. The mesostructure of minerals was studied by crystal mineralogy，the meso-crack propagation was recorded by a high-speed camera，and the microstructure of the fracture surface of the samples was observed by energy dispersive spectrometer(EDS) and scanning electron microscopy(SEM). The roughness of the fracture was calculated quantitatively with the fractal principle. The experimental results show that the mesostructure of granite minerals has an important influence on the spallation failure，especially for feldspar，quartz and mica which are the main components of granite. The distribution of these minerals also affects the expansion of mesoscopic cracks. It is also demonstrated from the microscopic analysis of EDS and SEM images that different minerals present different micro-fracture characteristics and that the fragmentation degree and roughness of the fracture increase with increasing the impact load，which was greatly validated by the fractal dimension values.
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2019, Vol. 38 
