Cracking Mechanism of Deep-Sea Cobalt-Rich Crusts with Water Jet

Dynamic simulation model of cobalt-rich crusts cracking process with water jet was estabLished and the cracking process was simulated with numerical calculation. With simulation research, cobalt-rich crusts water jet cracking mechanism is obtained. Simulation results show that during the cracking process, there is an initial crack in cobalt-rich crusts surface, which is generated by compressive crack. When the initial crack is formed, tensile crack and shear crack are generated in the inner of cobalt-rich crusts and the cracking speed is accelerated. A threshold pressure is exists in cobalt-rich crusts cracking process with water jet. When water jet pressure is less than the threshold pressure, the crack can´t be generated. When water jet pressure is great than the threshold pressure, with the increasing of water jet pressure, the cracking depth is increased quickly. Experimental tests were carried out to vaLidate simulation conclusions. Experimental results show that during water jet cracking process, a threshold pressure is existed, which is great than cobalt-rich crusts simulation materials compressive strength. With the increasing of water jet pressure, cracking speed and depth of simulation materials is increased obviously.