To reveal the fracturing mechanism and crack expansion rule of concrete under high pressure water jet impact, this paper established the numerical model of high pressure water jet impacting meso concrete based on the coupling method of Finite Element Method (FEM) and Smoothed Particle Hydrodynamics (SPH), which was verified utilizing Digital Image Correlation (DIC) and Computed Tomography (CT) technologies. Results indicate that a crater is generated under the strong water hammer pressure of water jet, and due to the existence of aggregate, the repetitious superposition of stress waves causes the irregular shape of the crater. In the intense action zone of water jet, the crack at protruding part of aggregate firstly appears and then connects to the crater or the other protruding part of the adjacent aggregate, forming the connecting cracks between aggregate and aggregate. And when the crack tips meet aggregate at a large angle, the energy of concrete can be fully released to aggregate, causing the crack penetrating aggregate. In the weak action zone of water jet, the decreases of stresses in concrete induce that cracks prefer to propagate along aggregate. Besides, with the sustained impact of water jet, the crater gradually enlarges, and internal cracks propagate to the boundary of concrete to form flank cracks, finally, the concrete takes place the whole debacle with the expansions and fusions of the internal cracks and the flank cracks.

为揭示高压水射流冲击下混凝土的破裂机理和裂纹扩展规律，本文基于有限元法（FEM）和光滑粒子流体力学（SPH）的耦合方法，建立了高压水射流冲击细观混凝土的数值模型。 )，这是利用数字图像相关 (DIC) 和计算机断层扫描 (CT) 技术进行验证的。结果表明，在水射流强烈的水锤压力作用下，形成了一个陨石坑，并且由于骨料的存在，应力波的重复叠加导致了陨石坑的不规则形状。在水射流强烈作用区，骨料突出部分的裂缝首先出现，然后与火山口或相邻骨料的其他突出部分相连，形成骨料与骨料之间的连接裂缝。当裂缝尖端与骨料大角度相遇时，混凝土的能量可以充分释放给骨料，导致裂缝穿透骨料。在水射流弱作用区，混凝土中应力的降低导致裂缝更倾向于沿骨料扩展。此外，随着水射流的持续冲击，火山口逐渐扩大，内部裂缝扩展到混凝土边界形成侧翼裂缝，最终随着内部裂缝和侧翼的膨胀和融合，混凝土发生整体溃烂。裂缝。混凝土中应力的降低导致裂缝更倾向于沿骨料传播。此外，随着水射流的持续冲击，火山口逐渐扩大，内部裂缝扩展到混凝土边界形成侧翼裂缝，最终随着内部裂缝和侧翼的膨胀和融合，混凝土发生整体溃烂。裂缝。混凝土中应力的降低导致裂缝更倾向于沿骨料传播。此外，随着水射流的持续冲击，火山口逐渐扩大，内部裂缝扩展到混凝土边界形成侧翼裂缝，最终随着内部裂缝和侧翼的膨胀和融合，混凝土发生整体溃烂。裂缝。