This study presents a numerical investigation on the fracture mechanism of tension stiffening phenomenon in reinforced concrete members. A novel approach using the discrete element method (DEM) is proposed, where three-dimensional randomly generated distinct polyhedral blocks are used, representing concrete and one-dimensional truss elements are utilized, representing steel reinforcements. Thus, an explicit representation of reinforced concrete members is achieved, and the mechanical behavior of the system is solved by integrating the equations of motion for each block using the central difference algorithm. The inter-block interactions are taken into consideration at each contact point with springs and cohesive frictional elements. Once the applied modeling strategy is validated, based on previously published experimental findings, a sensitivity analysis is performed for bond stiffness, cohesion strength, and the number of truss elements. Hence, valuable inferences are made regarding discontinuum analysis of reinforced concrete members, including concrete–steel interaction and their macro behavior. The results demonstrate that the proposed phenomenological modeling strategy successfully captures the concrete–steel interaction and provides an accurate estimation of the macro behavior.

这项研究提供了一个数值研究钢筋混凝土构件中的拉伸硬化现象的断裂机理。提出了一种使用离散元方法（DEM）的新颖方法，其中使用了三维随机生成的不同多面体块，代表混凝土，而使用一维桁架单元，代表钢筋。因此，获得了钢筋混凝土构件的明确表示，并通过使用中心差算法对每个砌块的运动方程进行积分来解决系统的机械性能。在每个接触点都考虑到了弹簧和内聚摩擦元件之间的块间相互作用。一旦根据先前发布的实验结果验证了应用的建模策略，对粘结刚度，内聚强度和桁架单元的数量进行敏感性分析。因此，对钢筋混凝土构件的间断分析做出了有价值的推论，包括混凝土与钢之间的相互作用及其宏观行为。结果表明，所提出的现象学建模策略成功捕获了混凝土与钢之间的相互作用，并提供了对宏观行为的准确估计。