摘要
本文根据材料细观断裂机理研究了Ⅰ─Ⅱ复合型裂纹尖端区域发生韧性断裂的力学条件，并考察它们与Ⅰ─Ⅱ型裂纹断裂参量的关系。结果表明：Ⅰ—Ⅱ型裂尖张开位移矢量的Ⅰ型分量δＩ与裂尖区材料在受载变形中积累的宏观空洞扩张比ⅤＧ有密切的对应关系；现有的ＣＯＤ和文［２］中的δＩ参量均表征了裂尖区早期形核空洞的扩张。
n this paper, mechanical conditions of ductile fracture in crack -tip vicinities of mixed Ⅰ and Ⅱ modes and their relations to fracture criteria of the.cracks were investigated based on the mesomechanisms of fracture. The results indicate that modeⅠcomponent,δI, of the crack -tip opening displacement vector,of Ⅰ-Ⅱmixed modes is closely related to the void growth rate, VG accumulated during loading and distortion of material in the crack -tip vicinities, and that the δI proposed in ref. [2],as well as the COD, characterizes the growth of voids nucleated early in the vicinities of the crack -tip.
关键词
复合型断裂
弹塑性断裂
空洞扩张
mixed mode fracture
elastic-plastic fracture criteria
mesomechanics
