预应力钢-混凝土连续组合梁的非线性有限元分析

Nonlinear finite element analysis of prestressed continuous steel-concrete composite beams

以六根两跨预应力钢-混凝土连续组合梁的系列试验结果为基础,以通用有限元程序MSC.MARC(2005 r2)为平台,提出用于模拟预应力连续组合梁非线性全过程受力行为的精细有限元模型,并给出单元选取、材料建模以及整体组装的详细过程。有限元分析基于弹塑性本构模型,能充分考虑材料非线性和几何非线性,反映结构受力全过程中预应力筋内力变化、滑移效应、内力重分布、应力分布、曲率分布以及塑性铰形成等复杂特性,深入揭示预应力连续组合梁的受力机理和特点。模型计算结果和实测结果以及理论分析结果吻合良好,表现出良好的数值特性。模型对于预应力连续组合梁的精细化分析具有较高的精度和广泛的适用性,为研究预应力连续组合梁受力性能提供了强有力的工具。

Based on the experimental results of six two-span prestressed continuous steel-concrete composite beams,an elaborate finite element model is proposed for simulating the nonlinear behavior of prestressed continuous composite beams using the commercial FE package MSC.MARC（2005r2）.The procedures for element selection,material modeling and monolithic assembly are presented in detail,using an elasto-plastic constitutive model.The numerical model considering both the material and the geometric nonlinearities can fully reflect the complex characteristics such as the change of tendon force,slip effect,redistribution of internal force,stress distribution,curvature distribution,formation of plastic hinges,etc..As the finite-element results are in good agreement with the test results and the theoretical analysis,the proposed finite-element model provides a tool for nonlinear analysis of prestressed continuous composite beams.