Weibull应力方法预测低合金钢的韧脆转化曲线  

PREDICTION OF THE DUCTILE-BRITTLE TRANSITION CURVE OF FERRITIC STEELS USING WEIBULL STRESS METHODOLOGY

作　　者：陈忠安[1] 徐冉[1] 曾振[1] 

机构地区：[1]江苏大学理学院,江苏镇江212013

出　　处：《工程力学》2007年第12期25-30,共6页Engineering Mechanics

基　　金：江苏大学科研基金项目(1281190001)

摘　　要：采用三参数的Weibull分布描述断裂韧度的统计规律。结合ASTM E1921-05标准,详细讨论了标准断裂试样韧脆转化曲线的建立过程;为了将标准断裂试样的测试结果用于低约束断裂试样,采用两参数的Weibull分布描述裂纹尖端局部区域的应力状态与失效概率之间的关系,并用Weibull应力将各种不同约束水平的裂纹尖端应力场联系起来,得到了预测低约束断裂试样韧脆转化曲线的公式。然后对两种A533B钢三点弯曲断裂试样进行了实例计算,进一步分析了Weibull应力的有限元计算结果,根据这些结果预测的韧脆转化曲线与试验数据相比非常吻合,证明了该文提出的方法是有效的。The three-parameter Weibull distribution is used to characterize the statistic law of fracture toughness. The procedure to establish ductile-brittle transition curve of standard specimens is discussed according to ASTM E1921-05. In order that the experiment results can be applied to low constraint specimens, the two-parameter Weibull distribution is used to describe the relationship between local stress state in crack tip and failure probability. Then, crack tip stress field under different constraint levels can be matched each other by Weibull stress and the equation to predict ductile-brittle transition curve of ferritic steel is concluded. The finite element analysis is aim at two three-point bend specimens made of A533B steel and the relevant Weibull stress is performed. The predictions of ductile-brittle transition curve according to the procedure are well consistent with experiment data. This illustrates the validity of the present approach.

关 键 词：断裂韧度 Weibull应力 韧脆转化曲线 约束 有限元 

分 类 号：O346[理学—固体力学]