摘要
混凝土损伤模型的研究,实质上是研究损伤变量对混凝土材料本构关系的影响。在外界因素作用下,材料的累积变形引起结构内部损伤的发展,最终将产生宏观裂缝直至破坏。在混凝土损伤破坏过程中,"凹凸无序"的断裂面和"杂乱无章"的裂缝是对混凝土宏观力学性能离散化、非线性、随机性的最直接的体现和表征。基于断裂面和裂缝的分形特性,得到了分形应力、分形应变的基本概念,使之能更为准确地描述混凝土的宏观力学性能。通过Najar能量损伤理论,利用分形应力与表观应力、多重分形应变与表观应变之间的关系,推导得出了混凝土分形损伤本构模型,重新定义了Weibull概率分布的混凝土损伤扩展规律,得到了基于压缩变形分形特性的损伤演化方程。
Concrete damage model research,in fact is the study of concrete material damage variables influence on its constitutive relationship.Cumulative deformation of material can cause interior damage of structure under exterior load so that the entire structure may collapse due to damage of concrete.In the process of concrete damage,the irregular fracture surfaces and wandering or disorderly cracks are the most direct embodiment and characterization for concrete mechanics performance discretization.In order to accurately describe concrete mechanics performance,the conception of fractal stress、fractal strain and fractal fracture energy are obtained by the fractal characteristics of the fracture surface.According to energy dissipation damage theory by Najar,the uniaxial tensile fractal damage constitutive model is put forward by combining fracture mechanics with continuum damage mechanics.By means of redefined damage propagation law of Weibull probability distribution,a new damage evolution equation considering the fractal characteristics of concrete fractures is proposed.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2015年第21期21001-21006,共6页
Journal of Functional Materials
基金
国家科技支撑计划资助项目(2013BAJ08B03)
国家自然科学基金资助项目(50978218
51108376)
关键词
混凝土
分形应力
多重分形应变
Najar能量损伤理论
分形损伤本构模型
分形损伤演化方程
concrete
fractal stress
multi-fractal strain
energy dissipation damage theory by Najar
fractal dam-age constitutive model
fractal damage evolution equation
作者简介
郑山锁（1960-）,男,陕西渭南人,教授,博士生导师,主要从事高强高性能混凝土材料研究.
