疲劳荷载作用下的三维弹塑性弯曲裂纹尖端张开位移
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摘要
综合考虑疲劳作用应力、三维塑性区域边界上的交变正应力与交变剪应力,利用二阶摄动方法建立了计算疲劳载荷作用下三维弹塑性弯曲裂纹尖端张开位移的理论模型。用数值解法进行求解,并作图分析了三维弹塑性弯曲裂纹尖端张开位移的最大值和变化幅值与三维裂纹体几何尺寸及外载荷之间的变化关系。结果表明,随着裂纹体厚度的增大,三维弹塑性弯曲裂纹尖端张开位移的最大值与变化幅值不断减小;当裂纹体几何尺寸相同时,弯曲裂纹尖端张开位移的最大值与变化幅值均随外载荷的增加而逐渐增大。
Taking the effects of fatigue stress,cyclic normal and shear stresses on the boundaries of three dimensional plastic area into consideration,this paper has built the theoretical models to calculate three dimensional elastic-plastic curved crack tip opening displacement(CCTOD)under fatigue loads by using second order perturbation method.Numerical solutions were made,and the relation curves between the maximum or amplitude of CCTOD and the crack body geometrical dimensions as well as the external loads were analyzed.The results show that the maximum and amplitude of CCTOD decline with the increase of crack body thickness.When crack bodies have the same size,the maximum and amplitude of CCTOD increase with increasing external loads.
Taking the effects of fatigue stress,cyclic normal and shear stresses on the boundaries of three dimensional plastic area into consideration,this paper has built the theoretical models to calculate three dimensional elastic-plastic curved crack tip opening displacement(CCTOD)under fatigue loads by using second order perturbation method.Numerical solutions were made,and the relation curves between the maximum or amplitude of CCTOD and the crack body geometrical dimensions as well as the external loads were analyzed.The results show that the maximum and amplitude of CCTOD decline with the increase of crack body thickness.When crack bodies have the same size,the maximum and amplitude of CCTOD increase with increasing external loads.
引文
[1]黄学伟,蔡力勋,包陈,等.基于低周疲劳损伤的裂纹扩展行为数值模拟新方法[J].工程力学,2011,28(10):202-208.
[2]廖芳芳,王伟,陈以一.往复荷载下钢结构节点的超低周疲劳断裂预测[J].同济大学学报:自然科学版,2014,42(4):539-547.
[3]嵇醒.断裂力学判据的评述[J].力学学报,2016,48(4):741-753.
[4]王清远,刘永杰.结构金属材料超高周疲劳破坏行为[J].固体力学学报,2010,31(5):496-503.
[5]魏国前,岳旭东,党章,等.结合S-N曲线和断裂力学的焊接结构疲劳寿命分析[J].焊接学报,2017,38(2):23-27.
[6]Zhao Minghao,Dang Huayang,Xu Guangtao,et al.Dielectric breakdown model for an electrically semi-permeable penny-shaped crack in three-dimensional piezoelectric media[J].Acta Mechanica Solida Sinica,2016,29(5):536-546.
[7]Yang Shengqi,Huang Yanhua,Ranjith P G,et al.Discrete element modeling on the crack evolution behavior of brittle sandstone containing three fissures under uniaxial compression[J].Acta Mechanica Sinica,2015,31(6):871-889.
[8]丁遂栋,孙利民.断裂力学[M].北京:机械工业出版社,1997:148-169.
[9]杨卫.宏微观断裂力学[M].北京:国防工业出版社,1995:65-70.
[10]杨大鹏,赵耀,白玲.准静载作用下弹塑性微弯裂纹尖端塑性区[J].应用力学学报,2010,27(2):401-405.
[11]郭万林,于培师.构件三维断裂与疲劳力学及其在航空工程中的应用[J].固体力学学报,2010,31(5):553-571.
[12]张斌.材料结构宏观三维断裂和微观破坏行为研究[D].南京:南京航空航天大学,2005.
[13]杨大鹏.微弯延伸裂纹断裂特性的研究[D].武汉:华中科技大学,2006.
[2]廖芳芳,王伟,陈以一.往复荷载下钢结构节点的超低周疲劳断裂预测[J].同济大学学报:自然科学版,2014,42(4):539-547.
[3]嵇醒.断裂力学判据的评述[J].力学学报,2016,48(4):741-753.
[4]王清远,刘永杰.结构金属材料超高周疲劳破坏行为[J].固体力学学报,2010,31(5):496-503.
[5]魏国前,岳旭东,党章,等.结合S-N曲线和断裂力学的焊接结构疲劳寿命分析[J].焊接学报,2017,38(2):23-27.
[6]Zhao Minghao,Dang Huayang,Xu Guangtao,et al.Dielectric breakdown model for an electrically semi-permeable penny-shaped crack in three-dimensional piezoelectric media[J].Acta Mechanica Solida Sinica,2016,29(5):536-546.
[7]Yang Shengqi,Huang Yanhua,Ranjith P G,et al.Discrete element modeling on the crack evolution behavior of brittle sandstone containing three fissures under uniaxial compression[J].Acta Mechanica Sinica,2015,31(6):871-889.
[8]丁遂栋,孙利民.断裂力学[M].北京:机械工业出版社,1997:148-169.
[9]杨卫.宏微观断裂力学[M].北京:国防工业出版社,1995:65-70.
[10]杨大鹏,赵耀,白玲.准静载作用下弹塑性微弯裂纹尖端塑性区[J].应用力学学报,2010,27(2):401-405.
[11]郭万林,于培师.构件三维断裂与疲劳力学及其在航空工程中的应用[J].固体力学学报,2010,31(5):553-571.
[12]张斌.材料结构宏观三维断裂和微观破坏行为研究[D].南京:南京航空航天大学,2005.
[13]杨大鹏.微弯延伸裂纹断裂特性的研究[D].武汉:华中科技大学,2006.