基于近场动力学理论的腐蚀疲劳裂纹扩展数值模拟  

Numerical simulation of corrosion fatigue crack propagation based on peridynamics theory

作　　者：卫少东 钱松荣[2] 周诗云 郑鑫 侯怡 WEI Shaodong;QIAN Songrong;ZHOU Shiyun;ZHENG Xin;HOU Yi(School of Mechanical Engineering,Guizhou University,Guiyang 550025,China;State Key Laboratory of Public Big Data,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学机械工程学院,贵阳550025 [2]贵州大学省部共建公共大数据国家重点实验室,贵阳550025

出　　处：《机械强度》2025年第4期70-78,共9页Journal of Mechanical Strength

基　　金：贵州省科技计划项目(20195802,20192886)。

摘　　要：为了模拟腐蚀疲劳的裂纹扩展,提出了一种近场动力学腐蚀-疲劳断裂耦合模型,并将该模型应用于A7N01PT4铝合金的裂纹扩展模拟分析。在该模型中,用氢和应力的交互作用体现腐蚀中阳极溶解和氢致开裂两种机制之间的协同作用,在量化材料因腐蚀产生断裂行为时,将腐蚀求解步骤和力学求解步骤进行耦合。由于氢使材料的塑性降低并发生脆性断裂,在研究中采用适合模拟各向同性脆性破坏的键型近场动力学理论,并使用准脆性材料的本构力函数来描述近场力与伸长率之间的关系,该函数包含线性和非线性力学行为。通过将仿真结果与A7N01P-T4铝合金在3.5%NaCl溶液中的试验结果进行比较,发现两者之间吻合较好,从而验证了该模型的可行性。In order to simulate the crack propagation by corrosion fatigue,a coupled peridynamics corrosion-fatigue fracture model was proposed and applied to the simulation and analysis of crack propagation in A7N01P-T4 aluminum alloy.In this model,the interaction of hydrogen and stress was used to reflect the synergy between the two mechanisms of anodic dissolution and hydrogen cracking in corrosion,and the corrosion solution step and the mechanical solution step were coupled when quantifying the fracture behavior of the material due to corrosion.Since hydrogen reduces the plasticity of the material and brittle fracture occurs,a bonded peridynamics theory suitable for simulating isotropic brittle damage was used,and the relation between near-field force and elongation was described using an intrinsic force function for quasi-brittle materials that incorporates both linear and nonlinear mechanical behavior.The feasibility of the model is verified by comparing the simulation results with the test results of A7N01P-T4 aluminum alloy in 3.5% NaCl solution,and it is found that the results are in good agreement between them.

关 键 词：近场动力学理论 本构方程 腐蚀疲劳 阳极溶解 裂纹扩展 

分 类 号：O342[理学—固体力学]