Biosketch

Dr. Xuhai Tang is professor at Wuhan University. He obtained PhD degree at Imperial College London, and has been a research assistant at Princeton University. He is the editorial board member of the “International Journal of Rock Mechanics and Mining Sciences”. His group developed the AiFrac-TOUGH simulator and microscale Rock Mechanics Experiment (micro-RME) system, in order to understand, predict and control the behavior of fractured rocks with Hydraulic-Mechanical-Thermal coupling process. The micro-RME system, including nanoindentation testing and AFM testing, is developed to investigate the micro-cracking and mechanical property of rock-forming minerals. The AiFrac-TOUGH is developed for modelling the three-dimensional fracturing, which contributes to the smarter unconventional petroleum production, thermal energy exploitation and space exploitation.

Introduction of the Lecture

The future human activities beyond Earth definitely need the development of geotechnical engineering. Understanding the cracking of rocks on asteroids is not only helpful for the optimizing of drilling, but also helpful for the investigation of impact history happened beyond Earth. In this work, the shock-induced melt veins in Hammadah al Hamra 346 asteroid meteorites are investigated numerically and experimentally, which records the impact history of their parent bodies. Firstly, the microstructure of minerals and shock-induced melt veins are achieved using TESCAN Integrated Mineral Analyzer (TIMA). Then, the physical and mechanical properties of minerals and shock-induced melt veins are measured using nanoindentation testing and Atomic Force Microscope (AFM) testing. Secondly, based on these experimental results, grain-based digital rocks can be generated for the meteorites. Thirdly, the AiFrac-TOUGH is extended to model the propagation of shock-induced melt veins. The evolutions of very high shock pressures, heat diffusion and impact heating induced by the impact between two asteroids are simulated, which leads to the cracking, melting and deformation of rocks. Meanwhile, the influence of different impact velocities on the propagation path of shock-induced melt veins is discussed.