Numerical analysis of RC wall with opening and strengthened with CFRP

Abstract The present work simulates and analyzes numerically two one-way walls (OW) with a central unforeseen cut-out-opening, which were previously tested experimentally. The models are based in the Finite Element Method and consider nonlinear behavior of the concrete material, such as hardening/softening and fracture. The first wall model was analyzed without any type of strengthening whereas the second one was strengthened using externally bonded CFRP along the opening edges. The strengthening modeling process was discussed through three different approaches suitable for unidirectional CFRP wrap. Load results were presented with load-displacement and load-strain curves that evidenced the flexural behavior of these structures. The crack pattern and failure mode observed showed good agreement with reported literature. The CFRP strengthening presented a small influence in the load capacity for big opening size.

摘要 本文对两片此前已完成试验测试的、中央带有意外开孔的单向墙体（one-way walls, OW）开展数值模拟与分析。本研究采用有限元法建立模型，考虑混凝土材料的硬化/软化特性与断裂行为等非线性力学行为。其中第一个墙体模型未进行任何加固处理，第二个墙体模型则沿开孔边缘采用外粘式碳纤维增强复合材料（Carbon Fiber Reinforced Polymer, CFRP）进行加固。针对单向碳纤维布包裹，本文通过三种不同方法对加固建模流程展开了讨论。研究通过荷载-位移曲线与荷载-应变曲线呈现荷载结果，直观反映了这类结构的受弯力学特性。观测得到的开裂模式与破坏形态与已有文献报道结果吻合良好。对于大尺寸开孔工况，碳纤维增强复合材料加固对结构承载能力的影响较为有限。