There are several techniques to simulate rebar reinforced concrete, such as smeared model, discrete model, embedded model, CLIS (constrained Lagrange in solid) model, and CBIS (constrained beam in solid) model. In this study, however, the interaction between the concrete elements and the reinforcement beam elements is only simulated by the discrete model and CBIS (constrained beam in solid) model. The efficiency and accuracy comparisons are investigated with reference to the analysis results by both models provided by LS-DYNA explicit finite element software. The geometric models are created using LS-PrePost, general purpose preprocessing software for meshing. The meshed models are imported to LS-DYNA where the input files are then analyzed. Winfrith and CSCM concrete material options are employed to describe the concrete damage behavior. The reinforcement material model is capable of isotropic and kinematic hardening plasticity. The load versus midspan deflection curves of the finite element models correlate with those of the experiment. Under the conditions of the same level of accuracy, the CBIS model is evaluated to have the following advantages over the discrete model. First, it has the advantage of reducing the time required for FE modeling; second, saving computer CPU time due to a reduction in total number of nodes; and third, securing a good aspect ratio of concrete elements.

中文翻译：

---

基于LS-DYNA的离散模型和CBIS模型的RC梁有限元分析

有多种模拟钢筋混凝土的技术，例如涂装模型，离散模型，嵌入式模型，CLIS（实体受约束的拉格朗日）模型和CBIS（实体受约束的梁）模型。然而，在这项研究中，混凝土构件与钢筋梁构件之间的相互作用仅通过离散模型和CBIS（实体受约束梁）模型进行模拟。参照LS-DYNA显式有限元软件提供的两个模型的分析结果，研究了效率和精度比较。使用用于网格划分的通用预处理软件LS-PrePost创建几何模型。网格化模型被导入到LS-DYNA，然后在其中分析输入文件。Winfrith和CSCM混凝土材料选项用于描述混凝土的破坏行为。增强材料模型具有各向同性和运动硬化性。有限元模型的载荷与中跨挠度曲线与实验相关。在相同精度水平的条件下，与离散模型相比，CBIS模型经过评估具有以下优点。首先，它具有减少有限元建模所需时间的优势；其次，由于减少了节点总数，因此节省了计算机CPU时间。第三，确保混凝土元件具有良好的长宽比。与离散模型相比，CBIS模型具有以下优点。首先，它具有减少有限元建模所需时间的优点。其次，由于减少了节点总数，因此节省了计算机CPU时间。第三，确保混凝土元件具有良好的长宽比。与离散模型相比，CBIS模型具有以下优点。首先，它具有减少有限元建模所需时间的优势；其次，由于减少了节点总数，因此节省了计算机CPU时间。第三，确保混凝土元件具有良好的长宽比。