超高强钢的颈缩极限应变测定方法比较分析  

Comparison and analysis of determination methods for necking limit strains of ultra high strength steel

作　　者：申逸菲 刘张 闵峻英[1] 刘鹏鹏[2] 魏一凡[2] 林建平[1] SHEN Yi-fei;LIU Zhang;MIN Jun-ying;LIU Peng-peng;WEI Yi-fan;LIN Jian-ping(School of Mechanical Engineering,Tongji University,Shanghai 201804,China;Pan Asia Technical Automotive Center Co.,Ltd.,Shanghai 202106,China)

机构地区：[1]同济大学机械与能源工程学院,上海201804 [2]泛亚汽车技术中心有限公司,上海202106

出　　处：《塑性工程学报》2022年第4期104-111,共8页Journal of Plasticity Engineering

摘　　要：针对3种不同强度级别的超高强钢DP980、QP1180和QP1500,开展了结合数字图像相关技术的Marciniak试验和Nakazima试验,采用包括空间法、时间法、时空法在内的6种颈缩极限应变测定方法对数据进行处理,获得了单向拉伸、平面应变和等双向拉伸路径下板料的颈缩极限应变,并分析了不同测定方法所得颈缩极限应变的结果差异。通过对比分析发现,在判断超高强钢材料的颈缩开始时刻时,采用空间法和时间法均不能获得具有较好准确性和鲁棒性的结果,而时空法基于试样表面的形貌变化,且同时考虑应变随时间的演化和在空间中的分布,具有较好的物理意义,采用时空法可以获得相对可靠的测定结果。For three kinds of different strength grades of ultra high strength steels DP980,QP1180 and QP1500,the Marciniak test and Nakazima test combined with digital image correlation technology were carried out,and six kinds of determination methods of necking limit strain including spatial method,temporal method and spatio-temporal method were used to data processing.The necking limit strain of sheet metal under paths of uniaxial tension,plane strain and equi-biaxial tension was obtained.The difference of necking limit strain results obtained by different determination methods was analyzed.Through comparison and analysis,it is found that the results obtained from spatial method and temporal method cannot get good accuracy and robustness when detecting the start time of necking of ultra high strength steel.The spatio-temporal method which is based on the change of the specimen surface geometry and considers the evolution with time and distribution in space of strain simultaneously is physically meaningful,and the determination results with relatively high reliability can be obtained.

关 键 词：颈缩极限应变 超高强钢 数字图像相关技术 

分 类 号：TH142.2[一般工业技术—材料科学与工程]