摘要
进行了最小应力水平为0.20fc,最大应力水平为0.20ft^0.55ft,定侧压为0.30fc的变截面混凝土试件三轴拉-压等幅和变幅疲劳试验,分析了混凝土三轴拉-压疲劳最大和最小纵向总应变的三阶段演变规律和级间相似性,给出了疲劳损伤演化规律。进一步验证了Miner线性损伤累积理论的不适用性,提出了非线性损伤累积模型,并进行了疲劳剩余寿命预测,通过与试验结果的比较表明该模型具有较高的精度和适用性。
Fatigue tests are conducted on tapered plain concrete prism specimens subjected to constant-amplitude or variable-amplitude triaxial tension-compression cyclic loading. The low level of the cyclic stress is 0.20fc and the upper level ranges between 0.20ft and 0.55ft. The constant lateral loading is 0.30fc. The three-stage evolution rule of the maximum and minimum longitudinal strains under constant-amplitude loading and its similarity under variable-amplitude loading are analyzed. The damage evolution law under both loading cases is obtained. Moreover, it is proved that Miner＇s rule is not applicable. A nonlinear cumulative damage model is established. Based on the model the residual fatigue life is predicted and compared with the experimental results. The better precision and applicability of the model is demonstrated.
出处
《工程力学》
EI
CSCD
北大核心
2006年第3期111-117,31,共8页
Engineering Mechanics
基金
国家自然科学基金资助项目(50078010)
关键词
混凝土
三轴拉-压疲劳
三阶段规律
Miner准则
非线性损伤累积模型
concrete
, triaxial tension-compression cyclic loading
three-stage evolution rule
Miner＇s rule
nonlinear cumulative damage model
