东篱科研大数据发现系统（DRDS）

位置：成果数据库 > 期刊 > 期刊详情页

多轴加载下混凝土细观破坏模拟的强度准则探讨

ISSN号：1007-4708
期刊名称：计算力学学报
时间：2015
页码：322-331
分类：TU528[建筑科学—建筑技术科学] O346[理学—固体力学;理学—力学]
作者机构：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124
相关基金：国家973计划（2011CB013600）; 国家自然科学基金重大项目（91215301）; 北京工业大学博士创新基金（YB201207）资助项目
相关项目：高坝、地下结构及大型洞室群地震灾变集成研究

关键词：混凝土, 细观尺度, 复杂加载, 强度准则, 破坏模拟, concrete, meso-scale, complex loading, strength criterion, failure simulation

中文摘要：

实际工程结构中混凝土材料大多处于双轴或三轴的复杂应力状态,已有的细观力学数值研究工作大多针对单轴加载问题,对于双轴或者三轴加载条件下混凝土破坏模拟的研究相对较少。复杂受力条件下的混凝土材料破坏模拟中,细观组分强度准则选取的合理与否将成为混凝土破坏模式及宏观力学性能数值研究准确和成功与否的关键。本文旨在探讨单轴强度准则,如最大拉应变准则在多轴加载条件下混凝土破坏过程研究中运用的合理性。鉴于此,首先在细观尺度上建立了混凝土试件的二维随机骨料模型,分别采用弹性损伤本构关系模型及塑性损伤本构关系模型来描述细观组分（即砂浆基质）的力学性能,对双轴加载条件下混凝土的细观破坏过程进行数值模拟,对比了单轴强度准则和多轴强度准则下混凝土试件破坏路径及宏观应力-应变关系的差异。数值结果表明,简单的单轴强度准则难以反映双轴加载下混凝土内部应力状态的复杂性,不宜采用单轴强度准则来描述多轴加载下混凝土的破坏行为。

英文摘要：

Concrete engineering structures often work under biaxial or tri-axial stress states,and most of the existed efforts were mainly concerned with the uniaxial mechanical properties of concrete.So far,little work has been conducted on the mechanical behavior of concrete under biaxial or tri-axial loadings.In the simulations for the meso-failure of concrete under complex loading conditions,whether the selected strength criterion is reasonable or not,will become a key factor that the numerical results of the failure modes and the macro-mechanical properties of concrete are accurate or not.The objective of the present study is to judge the rationality of the uniaxial strength criterion used in the meso-failure of concrete subjected to complex or multi-axial loadings,for instance,the maximum tensile strain criterion.In light of this,a two-dimensional random aggregate structure of concrete was established at meso-scale.An elastic damage model and a plasticity damage model were employed respectively to describe the mechanical performances of the concrete meso constituent（i.e.mortar matrix）,and the aggregate was set as elastic.Subsequently,the meso-scale failure processes of concrete under biaxial loading conditions were investigated.Moreover,a comparison was made between the failure paths and macroscopic mechanical properties of concrete obtained on the basis of the uniaxial strength criterion and the multi-axial strength criterion.The numerical results indicate that the uniaxial strength criterion is hard to describe the stress state complexity of concrete under biaxial loadings,and thus the uniaxial strength criterion is not suitable for description of the failure mechanism of concrete under complex loading conditions.