基于壳梁组合单元预应力混凝土梁非线性响应

Nonlinear Performance of Prestressed Concrete Beam with ShellBeam Composite Element

摘要:

基于壳梁组合(SBC)单元，建立了预应力混凝土T梁非线性分析模型,并对其进行了破坏全过程研究，对梁体刚度折减、预应力筋应力重分布规律等进行了分析.基于分层壳单元和梁单元计算模式，对预应力筋采用SBC单元模拟，有效地模拟了预应力筋的空间预应力作用，对普通钢筋和混凝土采用分层壳单元模拟.采用Owen准则等描述了预应力混凝土T梁的屈服等材料非线性效应，并研制了相应的非线性计算程序.研究结果表明，该方法的计算结果与试验梁的试验结果吻合良好，非线性SBC单元方法用于预应力混凝土T梁分析是合适的，为此类工程薄壁结构的评定分析提供了一种较为有效的计算方法.

关键词:桥梁工程; 预应力混凝土T梁; 壳梁组合单元; 刚度折减; 应力重分布

Abstract:

With the nonlinear shellbeam composite(SBC) element, the nonlinear analysis model of prestressed concrete T beam was established and the whole failure process was studied. The stiffness reduction and stress redistribution of T beam were analyzed. Based on the layered shell element and the beam element calculation model, the prestressed reinforcement was simulated by the SBC element, and the ordinary steel and concrete were simulated by the layered shell element. The material nonlinearity of prestressed concrete T beams was considered reasonably through Owen criterion and others. The spatial prestressing effect of the prestressed steel bar was simulated effectively and the corresponding nonlinear calculation program was developed. The calculation results of this method are in good agreement with the experimental results of the test beam, which shows that the nonlinear SBC element method is proper for the analysis of the structure. It provides an effective method for evaluating and studying this kind of thinwalled structures.

Key words:bridge engineering; prestressed concrete T beam; shellbeam composite element; stiffness reduction; stress redistribution