Digital Image Correlation (DIC) is applied to evaluate stress–strain diagrams for welded joints in two different ways. The first one is based on the measures strains along the welded joint, including all 3 zones of interest, base metal (BM), weld metal (WM), and heat-affected-zone (HAZ) subdivided into fine grain (FG) and coarse grain (CG) subzones. Specially designed iterative procedure has been used to determine coefficient of Holomon law to get true stress–strain curves for welded joint made of HSLA steel Niomol 490. The second one presents new methodology for evaluating true stress–strain diagram, based on measured values of contraction, as obtained by 3D DIC, rather than more conventional analytical formulas. New methodology is applied to undermatched welded joint, made of martensitic steels X10 CrMoVNb 9–1.

应用数字图像相关 (DIC) 以两种不同方式评估焊接接头的应力-应变图。第一个是基于沿焊接接头的应变测量，包括所有 3 个感兴趣的区域，母材 (BM)、焊缝金属 (WM) 和热影响区 (HAZ)，细分为细晶粒 (FG) 和粗粒 (CG) 亚区。使用专门设计的迭代程序来确定 Holomon 定律的系数，以获得由 HSLA 钢 Niomol 490 制成的焊接接头的真实应力 - 应变曲线。 第二个提出了基于收缩测量值评估真实应力 - 应变图的新方法，由 3D DIC 获得，而不是更传统的分析公式。新方法应用于由马氏体钢 X10 CrMoVNb 9-1 制成的欠匹配焊接接头。