NONLINEAR FINITE ELEMENT MODELING OF REINFORCED CONCRETE STRUCTURAL WALLS
NONLINEAR FINITE ELEMENT MODELING OF REINFORCED CONCRETE STRUCTURAL WALLS
复制标题
钢筋混凝土结构墙的非线性有限元建模
DOI：
10.13140/2.1.1778.6242
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
K. Orakcal
中科院分区：
文献类型：
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作者：
M. F. Gullu;K. Orakcal
提出了一种相对简单的有限元模拟方法，用于模拟具有不同程度的非线性弯曲和剪切耦合的钢筋混凝土结构墙的循环横向荷载行为。模型中包含的本构平板单元的行为特征是基于固定裂纹角的建模方法，该方法是一种有效的基于涂抹应力应变的压杆和拉杆方法，不需要特别的模型参数。本构模型还结合了混凝土中剪切-骨料-连锁效应和钢筋上的销钉作用的简单而有效的行为模型，构成了跨裂缝的剪应力传递机制。将模型应用于MatLab中，并将模型响应预测结果与试验测得的不同几何形状和配筋特征的墙体试件的反应进行了比较；包括长方形和T形截面的相对细长(高宽比为3.0)的墙，剪力控制反应的蹲式墙(高宽比为0.5)，以及剪弯相互作用反应为主的中等高耸墙(高宽比为1.5-2.0)。所提出的有限元建模方法对所研究的墙体试件的非线性滞回反应具有较高的预测精度。对试验测得的墙体反应属性进行了准确的预测，包括墙体的横向强度、刚度和延性，以及它们的滞回反应特性。该模型还提供了对非线性弯曲变形和剪切变形对墙体横向位移的相对贡献以及局部响应特征(例如应变分布)的准确估计。根据提供的响应比较，评估了模型的能力，并确定了可能的模型改进。总体而言，所提出的建模方法尽管其公式相对简单，但可以可靠地预测具有不同高宽比和响应特性的钢筋混凝土墙体的非线性水平荷载行为。
A relatively simple finite element modeling methodology was developed for simulating the cyclic lateral load behavior of reinforced concrete structural walls with varying levels of coupling between nonlinear flexural and shear response components. The behavioral characteristics of the constitutive panel elements incorporated in the model formulation are based on a fixed-crack-angle modeling methodology, which is effectively a smeared-stress-strain-based strut-and-tie approach that does not require ad-hoc model parameters. The constitutive panel model formulation also incorporates simple yet effective behavioral models for the shear-aggregate-interlock effects in concrete and dowel action on reinforcing bars, constituting the shear stress transfer mechanisms across the cracks. The model formulation was implemented into Matlab and model response predictions were compared with experimentally-measured responses of selected wall specimens with varying geometry and reinforcement characteristics; including relatively slender (aspect ratio of 3.0) walls with rectangular and T-shaped cross-sections, squat walls (aspect ratio of 0.5) with shear-controlled responses, and medium-rise walls (aspect ratios of 1.5–2.0) with predominant shear-flexure interaction responses. The proposed finite element modeling approach demonstrates a reasonable level accuracy in predicting the nonlinear hysteretic response of the wall specimens investigated. Accurate predictions are obtained for the experimentally-measured response attributes of the walls; including their lateral strength, stiffness, and ductility, as well as their hysteretic response characteristics. The model also provides accurate estimates of the relative contribution of nonlinear flexural and shear deformations to wall lateral displacements, and local response characteristics (e.g., strain distributions). Based on the response comparisons presented, model capabilities are assessed and possible model improvements are identified. Overall, the modeling approach proposed, despite its relatively simple formulation, is shown to provide reliable predictions of the nonlinear lateral load behavior of reinforced concrete walls with various aspect ratios and response characteristics.