论文部分内容阅读
In-situ dynamic cracking inside opaque geomaterials is desired to be understood but cannot be visualized using traditional optical imaging methods.In this study,the in-situ internal dynamic failure mechanisms in a concrete and Indiana limestone under dynamic loading was studied using high speed synchrotron X-ray phase contrast imaging.Dynamic compressive loading was applied using a modified Kolsky bar and fracture images were recorded using a synchronized high speed synchrotron X-ray imaging setup.3-D synchrotron X-ray tomography was also performed to record the microstructure of the specimens before dynamic loading.In the concrete,both straight cracking and angular cracking with respect to the direction of loading were observed.In limestone,cracks followed the grain boundaries and voids before ultimately fracturing the specimen.The effects of the microstructure on the observed dynamic crack behavior are discuss.