混凝土双轴压-压细观统计损伤本构模型  

Statistical Damage Constitutive Model for Concrete Under Biaxial Compression

作　　者：白卫峰[1] 管俊峰[1] 崔莹[2] 陈健云[3] 

机构地区：[1]华北水利水电大学水利学院,河南郑州450011 [2]黄河勘测规划设计有限公司,河南郑州450003 [3]大连理工大学建设工程学院,辽宁大连116024

出　　处：《四川大学学报（工程科学版）》2013年第6期74-81,共8页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金青年基金资助项目(51009020;51209094);华北水利水电大学高层次人才科研启动资助项目(201109)

摘　　要：细观损伤机制对混凝土材料宏观力学性能产生重要的影响。基于细观统计损伤理论及宏观试验现象,建立了混凝土双轴压-压细观统计损伤本构模型。考虑断裂、屈服2种细观损伤因素,损伤演化过程由主方向的压应变驱动;引入等效传递拉损伤应变的概念,受压方向的压损伤由侧向拉损伤应变控制。采用该模型对双轴压-压应变比例加载路径下应力-应变曲线形成的包络面进行了预测,提取出双轴压-压强度包络线;从双轴强度、变形特性、包络面形状等角度对材料的双轴压缩损伤机制进行探讨。结果表明:该模型能够有效模拟双轴压-压加载情况下混凝土材料宏观力学行为,能够揭示细观损伤演化机制;细观屈服损伤模式在材料变形破坏过程中起到决定性作用,将整个变形过程分为统计均匀损伤及局部破坏2个阶段;区分峰值应力状态和局部破坏的临界状态,建议后者作为本构模型的最终破坏点。Microscopic damage mechanism has an important impact on the macroscopic mechanical properties of concrete materials. Based on the statistical damage theory and the experimental phenomena, a statistical damage constitutive model for concrete under biaxi- al compression was proposed, in which two microscopic damage modes, rupture and yield,were considered. The whole damage evolution process was driven by the principal compressive strain. The concept of ＂equivalent transfer tensile damage strain＂ was introduced, and the compressive damage in press direction was controlled by the lateral tensile damage strain. By this model, the envelope composed of the stress-strain curves under biaxial compressive proportional load path was predicted. Furthermore, the strength envelope was ob- tained. The damage mechanism of concrete under biaxial compression was discussed from the view points of biaxial strength, deforma- tion properties and the envelope shape. The results showed that it can accurately reflect and predict the constitutive behavior of concrete under biaxial compression, and reveal the microscopic mechanism of damage evolution. The yield damage mode plays a critical role, by which the whole deformation and failure process can be divided into the statistical uniform damage phase and the local failure phase. The two characteristic states, the peak nominal stress state and the critical state when macro-crack appears, were distinguished, and the latter was proposed as the final failure point in the constitutive model.

关 键 词：混凝土 双轴压缩 细观统计损伤 本构模型 应力-应变曲线 

分 类 号：O319.56[理学—一般力学与力学基础]