摘要
传统的岩石疲劳本构模型对循环加卸载次数敏感性方面存在明显不足,无法准确描述残余变形与疲劳损伤进程的关系。在蠕变与疲劳试验基础上,通过对岩石蠕变和疲劳的时间(循环次数)与变形归一化,分析验证了两者间存在某种"同源性"。运用流变理论描述疲劳荷载下岩石变形全过程,基于等寿命Gerber曲线方程与Goodman直线方程,提出了通过疲劳寿命与应力关系的方式,定义了一种新的疲劳应力等效方法。用村山黏弹塑性体替换Kelvin黏弹性体,并加入开关函数和岩石完整度参数对Bingham黏塑性体进行改造,建立了一种新的7参数岩石非线性疲劳变形本构模型。该模型能较好地表征疲劳荷载下岩石减速、等速和加速疲劳变形的全过程,其加速疲劳变形段的完整度参数随着循环次数N增加而减小,能够体现疲劳损伤对加卸载次数因素的敏感性。
The traditional damage model is insensitive to cycles of loading and unloading,and it is obviously inadequate for the characterization of fatigue deformation and failure of rock.Based on the creep and fatigue tests,the"homology"hypothesis of the two kinds of deformation is verified by normalizing the time(cycle number)and deformation of rock creep and fatigue.The rheological theory is used to describe the whole process of fatigue deformation of rock under fatigue loads,and susequently the improved fatigue stress equivalence is put forward based on the equal life curve equation,Gerber and Goodman linear equation.The Kelvin visco-elastomer is replaced by the Murayama visco-elastomer,and the switch function and rock integrity parameters are added to non-linear treatment of Bingham viscoplastic body to establish a 7-parameter non-linear fatigue model for rock.The results show that the model can characterize the whole process of rock deceleration,constant velocity and accelerated fatigue deformation under the fatigue loads.The integrity parameter decreases as the number of cycles,N,increases,and this trend reflects the sensitivity of the fatigue damage to factors of loading and unloading times.The research put a foundation for the long-term deformation prediction of engineering rock mass.
作者
唐欣
俞缙
林立华
高海东
李刚
林植超
TANG Xin;YU Jin;LIN Li-hua;GAO Hai-dong;LI Gang;LIN Zhi-chao(Fujian Research Center for Tunneling and Urban Underground Space Engineering,Huaqiao University,Xiamen 361021,China;Xiamen Road&Bridge Engineering Investment and Development Co.,Ltd.,Xiamen 361026,China;China Railway 18th Bureau Group Co.,Ltd.,Tianjin 300222,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2021年第1期102-111,I0004,共11页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51874144,51679093,42077254)
华侨大学研究生科研创新能力培育计划项目(18014086024)。
关键词
疲劳变形
应力等效
西原模型
村山体
非线性本构模型
fatigue deformation
stress equivalence
Nishihara model
Murayama
non-linear constitutive model
