预应力混凝土空间组合式滑移模型  

Spatial embedded slip model for analyzing prestressed concrete structures

作　　者：马诚[1] 陈惟珍[1] 

机构地区：[1]同济大学桥梁工程系,上海200092

出　　处：《应用力学学报》2014年第1期37-42,4,共6页Chinese Journal of Applied Mechanics

基　　金：交通部西部交通建设科技项目(200831849404)

摘　　要：考虑预应力钢筋和混凝土间的粘结滑移效应,结合组合式模型和分离式模型的优点,提出了一种预应力混凝土空间组合式滑移模型。通过预应力钢筋和混凝土单元交点处的虚拟结点,将模拟预应力钢筋和混凝土交界面的无厚度环形粘结单元嵌入组合单元中。粘结单元忽略预应力钢筋-混凝土间的径向相对位移,通过内、外表面的切向位移差值表征预应力钢筋的相对滑移量。基于位移有限元框架,根据预应力钢筋、混凝土、粘结单元各自的本构模型,由虚功原理推导出三者对组合单元刚度矩阵的贡献,建立了该空间组合式滑移模型的有限元平衡方程,并给出了有限元计算流程。在该模型中,预应力钢筋能以任意形式穿过混凝土单元而不需考虑其走向,网格划分灵活;对单个粘结单元而言,在平衡方程中缩减了2个虚拟结点的6个自由度,自由度数减少了8%。The bond-slip effect between prestressing tendon and concrete should be considered in nonlinear finite element analysis of prestressed concrete structures. A spatial embedded slip model is presented on combining advantages of embedded model and discrete model. The bond element simulating the interface of prestressing tendon and concrete is embedded into the composite element through virtual nodes on the intersection points of prestressing tendon and concrete element. The relative slip is obtained through the difference of tangential displacement between the inside and outside face of bond element, and the radial relative deformation between prestressing tendon and concrete is ignored. According to each constitutive model of prestressing tendon, concrete and bond element, stiffness contribution matrixes of three components are deduced and the finite element equilibrium equation is established through virtual work principle on the basis of displacement-based finite element method. Prestressing tendon can cross through concrete in any pattern without considering its direction and six freedoms of two virtual nodes in a single bond element can also be cut in the finite element equilibrium equation by using this slip model.

关 键 词：空间组合式滑移模型 虚拟结点 粘结单元 虚功原理 有限元平衡方程 

分 类 号：U448.35[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]