Cavitation damage is a micro, high-speed, multi-phase complex phenomenon caused by the near-wall bubble group collapse. The current numerical simulation method of cavitation mainly focuses on the collapse impact of a single cavitation bubble. The large-scale simulation of the cavitation bubble group collapse is difficult to perform and has not been studied, to the best of our knowledge. In this study, the equivalent model of impact loading of acoustic bubble collapse micro-jets is proposed to study the cavitation erosion damage of materials. Based on the theory of the micro-jet and the water hammer effect of the liquid–solid impact, an equivalent model of impact loading of a single acoustic bubble collapse micro-jet is established under the principle of deformation equivalence. Since the acoustic bubbles can be considered uniformly distributed in a small enough area, an equivalent model of impact loading of multiple acoustic bubble collapse micro-jets in a micro-segment can be derived based on the equivalent results of impact loading of a single acoustic bubble collapse micro-jet. In fact, the equivalent methods of cavitation damage loading for single and multiple near-wall acoustic bubble collapse micro-jets are formed. The verification results show the law of cavitation deformation of concrete using equivalent loading is consistent with that of a micro-jet simulation, and the average relative errors and the mean square errors are insignificant. The equivalent method of impact loading proposed in this paper has high accuracy and can greatly improve the calculation efficiency, which provides technical support for numerical simulation of concrete cavitation.

空化损伤是由近壁泡群坍塌引起的一种微观、高速、多相的复杂现象。目前空化的数值模拟方法主要集中在单个空化气泡的坍塌影响上。据我们所知，空化泡群坍塌的大规模模拟很难执行，也没有被研究过。本研究提出了声泡破裂微射流冲击载荷等效模型来研究材料的空化侵蚀损伤。基于微射流理论和液固冲击的水锤效应，在变形等效原理下建立了单个声泡破裂微射流的冲击载荷等效模型。由于可以认为声泡均匀分布在足够小的区域内，基于单个声泡冲击载荷的等效结果，可以推导出多个声泡破裂微射流在微段内的冲击载荷等效模型塌陷微射流。事实上，形成了单个和多个近壁声泡破裂微射流空化损伤加载的等效方法。验证结果表明，等效加载混凝土空化变形规律与微射流模拟一致，平均相对误差和均方误差均不显着。本文提出的冲击载荷等效方法精度高，可以大大提高计算效率，