冲击载荷下点蚀损伤对30CrMnSiNi2A钢应力集中影响的数值模拟研究

Numerical Simulation Study on the Effect of Pitting Damage on Stress Concentration of 30CrMnSiNi2A Steel Under Impact Load

对环境腐蚀和冲击载荷共同作用下30CrMnSiNi2A钢材料的动态力学响应进行了数值模拟分析,建立了钢材料在霍普金森杆试验中的模型,并将钢材料的腐蚀等效为分布在材料表面的腐蚀坑,计算分析了腐蚀坑位置、三维尺寸以及腐蚀坑分布对应变集中的影响,通过Python-Abaqus脚本程序建立了试件表面随机点蚀分布模型,计算了不同随机点蚀分布模型下,腐蚀试件的冲击动力学响应。研究结果表明:腐蚀坑位置对试件应变集中影响显著,侧面顶点处的应变集中系数最大,是中心位置处的2.328倍。蚀坑深度加重了应力集中,蚀坑长度会使应力发生分散,蚀坑宽度对应力集中并无明显影响。相邻蚀坑的应力集中随着蚀坑间距的增大呈现先增大后减小的特点,当蚀坑相距0.4 mm时,应变集中最为严重。试件表面随机分布的点蚀对试件侧面的影响大于试件端面,侧面处的蚀坑更容易发展成为损伤的源头。

The numerical simulation analysis of the dynamic mechanical response of 30 CrMnSiNi2 A steel material under the action of environmental corrosion and impact load was carried out.A model of steel material in the Hopkinson bar test is established,and the corrosion of steel material is equivalent to a corrosion pit distributed on the surface of the material.The effects of pit locations,threedimensional dimensions and pit distribution on strain concentration were calculated and analyzed.Finally,a random pitting distribution model on the surface of the specimen was established by the Python-Abaqus script program,and the impact dynamic response of the corrosion specimen under different random pitting distribution models was calculated.The research results show that the location of the corrosion pit has a significant effect on the strain concentration of the specimen,and the strain concentration factor at the side apex is the largest,which is 2.328 times the center position.The depth of the etch pits increases the stress concentration.The length of the etch pits will disperse the stress.The width of the etch pits has no significant effect on the stress concentration.The stress concentration of adjacent etch pits increases and then decreases with the increase of the pit pitch.When the pits are 0.4 mm apart,the strain concentration is the most severe.The random pitting on the surface of the specimen has a greater impact on the side of the specimen than the end surface of the specimen,and the pits on the side are more likely to develop into the source of damage.