中文摘要：

材料拉伸直至断裂的全程单轴本构关系对材料大变形和断裂机理研究具有重要意义．传统拉伸试验获取的材料真应力一真应变曲线在试样颈缩后不可测．借助可以精确测量三维变形的DIC（Digital image correlate）技术和有限元分析技术（Finite element analysis），论文提出了基于漏斗试样拉伸试验获取材料全程单轴本构关系的新方法，即TF（Test and FEA）方法．该方法将TF方法获取的材料全程单轴应力应变关系曲线作为有限元软件中的材料本构关系对漏斗试样拉伸变形过程进行模拟，其模拟载荷一位移曲线、漏斗根部直径位移曲线和漏斗变形轮廓线等均与试验结果吻合良好，试样表面模拟应变也与DIC测试结果吻合，根据不同半径漏斗试样模拟获得的全程真应力一真应变曲线保持良好一致性．最后，还对试样颈缩断面的力学行为进行了讨论，并给出了304不锈钢、汽轮机叶片材料2Cr12Ni4Mo3VNBN和1Cr12Ni3Mo2VN、汽轮机转子材料30Cr2Ni4MoV的全程单轴本构关系模型参数、破断应力和破断应变．

英文摘要：

The response of stress to strain of ductile materials from initial elastic deformation to final failure plays important role in their large deformation analysis and fracture mechanism study. The true stress-strain curve obtained by traditional tensile test becomes usually inaccurate after necking. For this, a new method to determine full-range uniaxial stress-strain curve of the ductile material is presented, which employs the Digital image correlate （DIC） technology to accurately measure mechanical 3D displacement and strain and the finite element analysis （FEA）. By inputting the full-range stress-strain curve obtained by this method into the finite element software and performing FEA on the funnel specimens,the load versus displacement curve, the funnel root diameter versus displacement curve, and the funnel deformation contours and the surface strain distribution are obtained, which show good agreement with test results. In addition,the influence of the funnel specimen size on the full-range true stress and strain curves is studied, which shows the stress-strain curve obtained by funnel specimens with different radius are well coincident with each other.