动态载荷下CoCrFeNiMn高熵合金的压入行为  

Indentation Behavior of CoCrFeNiMn High-Entropy Alloys under Dynamic Loads

作　　者：吴昆昆 刘聪 苏步云 邱吉 树学峰[1] 康正东 WU Kunkun;LIU Cong;SU Buyun;QIU Ji;SHU Xuefeng;KANG Zhengdong(Institute of Applied Mechanics,School of Aeronautics and Astronautics,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;Shanxi Construction Investment Group Co.,Ltd.,Taiyuan 030032,Shanxi,China)

机构地区：[1]太原理工大学航空航天学院应用力学研究所,山西太原030024 [2]山西省建设投资集团有限公司,山西太原030032

出　　处：《高压物理学报》2025年第4期44-55,共12页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(12302477,12272256);山西省基础研究自由探索项目(202203021222081)。

摘　　要：为解决材料或结构在服役环境中的内部应力难以评估的问题,提出了一种有限元与微压入测试相结合的方法。以CoCrFeNiMn高熵合金为例,分别在不同加载速度下开展了压缩、剪切和微压入测试,并基于非对称初始屈服函数、Swift硬化与关联流动法则,构建了该材料的弹塑性本构模型。利用应力积分算法将该本构模型程序化,并接入ABAQUS有限元软件中,通过对比分离式霍普金森压杆与压入模型的有限元模拟结果和实验结果,验证了模型的可靠性。基于分离式霍普金森压杆模型,进行了动态压缩实验的数值模拟,并将不同动态变形时刻的应力场作为初始应力场(内部应力)导入压入模型中,进行压入模拟分析。结果表明:加载阶段的初始应力场会显著降低相同压入深度下的压入载荷,且降低幅度随着初始应力的增加而增大;此外,初始应力场的存在会进一步减弱压入过程中的应力集中。通过对不同压缩量下的载荷-压入位移曲线进行定量分析,揭示了不同初始应力条件下材料的压入响应规律。研究结果为服役条件下材料或结构内部应力的评估提供了参考。To address the challenge of evaluating the internal stress of materials or structures in service environments,a method combining finite element analysis and micro-indentation testing is proposed.Taking the CoCrFeNiMn high-entropy alloy as the research object,compression,shear and micro-indentation tests were carried out at various loading speeds respectively.Based on an asymmetric initial yield function,Swift hardening and the associated flow rule,an elastoplastic constitutive model for this material was established.The constitutive model was programmed by using the stress integration algorithm and interfaced with the ABAQUS finite element software.Furthermore,by comparing the finite element simulation results with the experimental results from the split Hopkinson pressure bar(SHPB)tests and the indentation model,the reliability of the model was verified.Using the SHPB model,the numerical simulation of the dynamic compression experiment was carried out,and the stress fields at different dynamic deformation moments were imported into the indentation model as the initial stress(internal stress)fields for indentation simulation analysis.The results indicated that the initial stress field in the loading stage significantly reduces the indentation load at the same indentation depth,and the reduction amplitude increases with the increase of stress.In addition,the existence of the initial stress field will further weaken the stress concentration during the indentation process.Through the quantitative analysis of the load-indentation displacement curves under different compression amounts,the indentation response laws of the materials under different initial stress conditions were revealed.The research results provide a reference for the evaluation of the internal stress of materials or structures under service conditions.

关 键 词：分离式霍普金森压杆 本构方程 高熵合金 初始应力场 微压入 

分 类 号：O521.2[理学—高压高温物理] O347.3[理学—物理]