考虑损伤的混凝土非线性徐变模型  

Nonlinear creep model for concrete considering damage

作　　者：郑丹[1] 蔡昊男 李鑫鑫[1] ZHENG Dan;CAI Haonan;LI Xinxin(Department of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学河海学院,重庆400074

出　　处：《水利水电科技进展》2021年第4期75-80,共6页Advances in Science and Technology of Water Resources

基　　金：国家自然科学基金(51479013);重庆青年科技人才培养计划(cstc2014kjrc-qnrc30001);重庆交通大学研究生科研创新项目(2019S0125)。

摘　　要：采用断裂力学理论分析考虑徐变变形的材料内裂纹尖端实际能量释放率,研究持续荷载作用下混凝土内微裂纹应变能累积规律,认为在相同应变能累积情况下,长期持续荷载和单轴荷载下微裂纹扩展演化状态相同。基于柔度张量等效假设建立了混凝土的非线性徐变模型,实际应用表明,此模型与不同强度等级混凝土非线性徐变试验结果吻合较好,能反映混凝土损伤与徐变的耦合机理。The fracture mechanics theory was used to analyze the actual energy release rate at the tip of cracks in the material considering creep deformation.The strain energy accumulation law of microcracks in concrete under continuous loading was investigated and it is concluded that the microcrack extension evolution state is the same under long-term continuous loading and uniaxial loading with the same strain energy accumulation.This model is in good agreement with the results of non-linear creep tests on concrete of different strength classes.The coupling mechanism between concrete damage and creep can be reflected.

关 键 词：非线性徐变 混凝土 损伤 应变能 微裂纹 

分 类 号：TV315[水利工程—水工结构工程]