金属材料准静态断裂性能标准测试技术研究进展

Progress on the Standard Test Technology of Quasistatic Fracture Toughness for Metallic Materials

准静态断裂性能是评价含裂纹结构完整性的重要力学参量,其测试规范的制修订可反映国家在国际断裂测试领域的技术水平。由于较复杂的断裂力学理论背景以及长期经费投入乏力,我国的断裂性能测试规范自主创新修订工作严重落后于国际水平。自2011年立项至今,历经3年的不懈研究,完成了新版国家断裂测试规范GB/T 21143-2014的修订,且在原规范的基础上取得了许多新进展。主要包括:对基于柔度原理的裂纹长度计算公式进行了简化,完善了原有J积分和CTOD计算式;推荐了考虑断裂试样大角度转动影响的旋转修正新方法;借鉴ASTM E1820-11规范,引入了改良后的单试样规则化法。为了更好地促进新规范的推广应用,本文就新规范修订中涉及的上述技术的研究进展进行详细综述。

The quasistatic fracture toughnesses are key parameters in the integrity assessment of structures containing cracks, so the revision of testing specification for these parameters can evidently reflect the technological level in the field of fracture toughness testing. In view of complicated fracture mechanics background and long-standing short of financial support, the national self-renovation in the revision of fracture toughness testing specification slips far behind international level. From the project determination in 2011, the revision of testing specification GB/T 21143-2014 has been completed in 3 years, and greatprogresses have been made in comparison with the original version. The main revision of the new specification contains： a simplified formula of crack length estimation on the basis of compliance principle has been provided; the formulae for the calculation of J integral and CTOD have been improved; a new rotational correction method considering the large rotation effect on the fracture toughness determination has been recommended; by referring to ASTM E1820-11, a modified single specimen normalization method has been introduced. In order to promote the widespread application of this new specification, the progress of those related key techniques in this revision is reviewed in detail.