基于离散模型的混凝土构件破坏过程研究

刚体-弹簧元模型是一种离散化分析模型,可以反映连续体从开裂到破坏不连续过程的真实裂缝形态.论文在总结既有相关研究的基础上,引入并程序化刚体-弹簧元模型用于混凝土构件开裂破坏行为研究,特别是有关混凝土构件开裂后直至破坏的裂缝真实形态研究.首先确定了三维刚体-弹簧元模型中刚体单元的划分、弹簧元的特性(混凝土材料本构关系施加于弹簧元)、刚体单元与弹簧元装配方式、钢筋本构关系及其与混凝土相互作用,然后实现了刚体-弹簧元模型用于混凝土构件开裂破坏行为研究的程序化,并以剪切破坏的钢筋混凝土构件进行实例验证.结果表明,基于刚体-弹簧元模型的程序可以较为准确地反映该钢筋混凝土构件从开裂到破坏真实裂缝形态.

Study on discrete model for evaluating failure process of concrete member

Rigid body-spring model was one of discrete analysis models, which could reflect the realistic cracking pattern of continuum material during the discontinuous process from cracking to failure. This paper introduced and programmed the rigid body-spring model for studying the cracking and failure behavior of concrete member, especially realistic crack pattern of concrete member from cracking to failure, based on the summary of existing research result. The division of rigid body element, characteristics of spring element （the constitutive law of concrete applied to spring element）, assembly of rigid body and spring element, the constitutive law of rebar, and the interaction between rebar and concrete were determined firstly. After that, the programming on cracking and failure behavior of concrete member using rigid body-spring model was implemented and verified by a shear-failed RC member. The result demonstrated that the programming could exactly reflect the realistic crack pattern of the member from cracking to failure.