CTOA断裂准则的发展及应用

Development and Application of CTOA Fracture Criterion

对延性材料的稳态裂纹扩展机制和失稳断裂研究是断裂力学领域的重要研究方向之一。1973年Andersson在稳态裂纹扩展的有限元模拟中首次引进裂纹尖端张开角(CTOA)作为断裂准则,发现用CTOA作为断裂准则可有效地定量模拟稳态裂纹的扩展行为。近50年来,围绕CTOA断裂准则在描述裂纹扩展稳定性、影响因素、隧道效应、拘束效应,断裂过程有限元模拟等方面开展了广泛而深入的研究,并制定了确定CTOA的相关标准。CTOA作为断裂准则最大的优点在于采用二维和三维有限元分析,能准确模拟薄壁结构的稳态裂纹扩展行为,广泛适用于飞机机身、复杂的薄壁结构和长输管线等的裂纹扩展分析。就CTOA断裂准则的发展、标准化和应用等方面进行了简要综述,指出CTOA测量和应用中存在的主要问题和影响因素,并对未来的研究方向进行了展望。

Steady-state crack growth mechanism and unstable fracture of ductile materials is an important research direction of the fracture mechanics field.In 1973,Anderson first introduced the Crack Tip Opening Angle(CTOA)as a fracture criterion to the finite element simulation of steady-state crack growth,and found that CTOA,as the fracture criterion,can simulate the steady-state crack growth behavior effectively and quantitatively.In the past 50 years,wide and in-depth investigations were carried out in the aspects of crack growth stability,influencing factors,tunneling effect,constraint effect and finite element simulation of fracture process related to CTOA,and relevant standards for CTOA determination were developed.The biggest advantage of CTOA as a fracture criterion lies in that it can accurately simulate the steady-state crack growth behavior of thin-walled structures by using two-dimensional and three-dimensional finite element analysis.It has been widely used in crack growth analysis of aircraft fuselage,complex thin-walled structures and long-distance pipelines.In this paper,the development,standardization and application of CTOA fracture criteria are briefly reviewed,the main problems existing in measurement and application of CTOA are pointed out,and future prospect is also presented.