检查钢筋混凝土结构的开裂和破碎行为的有限元建模策略

金 城嘉, 亚历 山大
瑞典建筑与土木工程系

摘要

钢筋混凝土（RC）结构的非线性有限元（FE）分析的特点是众多建模选项和输入参数。为了准确模拟涉
及混凝土受拉开裂和受压压碎的非线性RC行为，从业者对关键建模问题做出不同的选择，例如，定义混凝土本构
关系，指定混凝土和钢筋之间的粘结，以及解决相关问题收敛困难和网格敏感性。因此，必须批判性地审查常见的
建模选择，并制定具有一致性、可靠性和可比性的稳健建模策略。本文基于关键建模选择的参数研究提出了一种建
模策略和实用建议，用于RC结构的非线性有限元分析。所提出的建模策略旨在为RC构件的弯曲响应提供可靠的预
测，重点是混凝土开裂行为和破碎破坏，这是更复杂建模案例的基础，例如，与纤维增强聚合物（FRP）层压板粘
合的RC梁。此外，本文全面描述了所提出的建模策略的实施过程，重点关注RC结构的关键建模问题。所提出的策
略通过对在四点弯曲中测试的RC梁进行有限元分析来证明——一根RC梁作为参考，一根梁在其拱腹处外部粘合有
碳 FRP（CFRP）层压板。模拟结果与关于荷载-变形关系、开裂、混凝土压碎引起的弯曲破坏以及中间裂缝引发的
CFRP剥离的实验测量结果非常吻合。本文提出的建模策略和建议通常适用于RC结构的非线性有限元分析。

关键词

钢筋混凝土；有限元分析；裂纹带；应变定位；峰后软化；粘塑性正则化；收敛；网格灵敏度；粘滑；弯 曲行为

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