考虑滑移效应的空间预应力混凝土组合式模型

提出一种考虑滑移效应的空间预应力混凝土组合式模型,通过预应力钢筋和混凝土交点处的虚拟节点,将模拟两者交界面的黏结单元嵌入滑移模型.基于位移有限元框架,由虚功原理推导滑移模型的有限元平衡方程,并编制计算程序.该模型允许预应力钢筋以任意形式穿过混凝土单元,网格划分灵活,虚拟节点的自由度在平衡方程的集成过程中得到约减.通过预应力混凝土矩形截面简支梁算例,滑移模型在材料弹性阶段计算结果的正确性得以验证,可作为预应力混凝土空间非线性有限元程序开发的基础.

A Spatial Prestressed Concrete Embedded Model with Consideration of Slip Effect

A spatial prestressed concrete embedded slip model, into which the non thickness bond element simulating the interface of prestressed tendon and concrete was embedded via virtual nodes introduced on intersection points of the two, was proposed. Based upon displacement based finite element framework, a finite element equilibrium equation for the slip model was deduced according to virtual work principle, and a related calculation program was developed. The proposed model allowed prestressed tendon to go through concrete in any pattern, without consideration of its layout and direction and therefore with convenience in finite element mesh. The freedoms of virtual nodes could be reduced in the formation of the equilibrium equation. Verified by a numerical example of simply supported prestressed concrete beam with rectangular section, the proposed model was proved to be correct in elastic calculation and could be further used to develop a three dimensional nonlinear finite element analyzing program.