基于平均应变能密度准则的裂纹断裂扩展特性分析  

Crack fracture and growth behavior based on averaged strain energy density criterion

作　　者：黄如旭[1] 谢晓忠 谢锋[1] 黄进浩[1] 万正权[1] HUANG Ru-xu;XIE Xiao-zhong;XIE Feng;HUANG Jin-hao;WAN Zheng-quan(State Key Laboratory of Deep-sea Manned Vehicles,China Ship Scientific Research Center,Wuxi 214082,China)

机构地区：[1]中国船舶科学研究中心深海载人装备国家重点实验室,江苏无锡214082

出　　处：《舰船科学技术》2020年第3期20-24,共5页Ship Science and Technology

摘　　要：考虑裂纹尖端应力场常数项T应力对裂纹断裂特性的影响,对平均应变能密度准则进行修正,建立混合型裂纹扩展条件计算式。在此基础上,系统分析常数项T应力对Ⅰ型、Ⅱ型、Ⅰ-Ⅱ混合型裂纹断裂判据的影响。结果表明,常数项T应力降低了材料裂纹起裂阻力,且参数|Bα|越大裂纹断裂极限值越低,|Bα|相同时,正T应力要比负T应力更容易发生断裂。基于修正平均应变能密度准则,预测双轴疲劳载荷作用下平板表面Ⅰ型裂纹扩展寿命。结果表明,考虑常数项T应力影响后的疲劳裂纹扩展寿命约为传统疲劳裂纹扩展寿命的49%。The averaged strain energy density criterion is modified by considering the constant term T-stress. The crack onset propagation formulation of mixed mode Ⅰ-Ⅱ-Ⅲ crack were then given. The mode Ⅰ, mode Ⅱ and mixed mode Ⅰ-Ⅱ crack onset propagation behavior were investigated thoroughly. The analysis results show that the crack onset propagation limit will be reduced by considering T-stress. The greater the parameter |Bα| is, the easier the fracture will take place. Fracture will more easily happen when the T-stress is positive at a given parameter |Bα|. The crack growth life of the plate surface mode Ⅰ crack under longitudinal tensile load and lateral compressive load simultaneously were analyzed based on the traditional reference variable ΔKΙ and the proposed reference variable ΔKeq. The analysis results show that T-stress has a significant effect on mode Ⅰ surface crack growth life, the crack growth life will be overestimated by neglecting the T-stress effect.

关 键 词：常数项 平均应变能密度准则 断裂判据 I型裂纹 裂纹扩展 

分 类 号：O346.1[理学—固体力学]