Fang WANG
金属学报(英文版)
A new model for the analysis of fatigue crack growth in the metal structures was proposed. This model shows a promising capability of explaining various fatigue phenomena. The new crack growth model is further completed by a continuous empirical formula for estimating the value of variable fracture toughness during crack propagation and a modified continuous equation for the crack tip stress/strain constraint factor used to calculate the stress intensity factor at the opening level. The prediction results are proved to agree well with the observed phenomena in test.
关键词:
Marine structures
,
Crack growth rate
,
Three dimensional stress state
,
Fracture toughness
,
Crack tip stress/strain constraint factor
高桦
,
曹卫杰
,
应虹
中国腐蚀与防护学报
提出了用非常规的圆截面小锥度光滑试样研究腐蚀疲劳(CF)裂纹扩展行为的新方法,即MST法(Multipe Small-angle-cone-specimen Test)。以黄铜在Mattson溶液中的腐蚀疲劳为例介绍了本方法的试验程序和结果。本方法所需要的试验装备简单、省时间、费用低,便于观察裂纹扩展与显微组织的关系,并且可测定多裂纹体系中表面裂纹朝纵深方向的扩展速率,在试验过程中不必停机及清洗试件使裂纹扩展的电化学环境和力学条件不受干扰,比较切合CF的真实情况。
关键词:
腐蚀疲劳
,
Crack growth rate
,
H68 Brass
王正
,
王志奇
中国腐蚀与防护学报
采用４３４０、１５和Ａ５０８三种结构钢，八种热处理状态；测定了它们在空气、海水和蒸馏水中的疲劳、应力腐蚀和腐蚀疲劳裂缝扩展速率，并进行了定量断口分析。在比较了叠加模型、竞争模型与实验结果的差异之后，提出了腐蚀疲劳裂缝扩展的韧带模型，拟出了该模型的计算程序。结果表明，尽管这个模型还比较粗糙，某些常数的决定还有点勉强，但由此估算的腐蚀疲劳扩展曲线，无论在形状和数值上，都与实验吻合；而它的简单方便，为工程应用提供了有利条件。
关键词:
腐蚀疲劳
,
Crack growth rate
,
Ligament model
