This study investigates the effect of support types on plastic hinges in reinforced concrete (RC) beam under the influence of impact loading. In previous studies, the assumption of the linear distribution of inertia force under impact loading was examined and verified according to experimental, analytical, and numerical results. Furthermore, it was emphasized that the most important parameters affecting the behavior of RC beams under impact loading were plastic hinges. A three-stage study was planned to investigate this subject. The first stage was an experimental study. In this part, four RC beams with simple and fixed supports were tested under the low-velocity impact load with two different impact energy levels by using a free-weight test setup with advanced measurement techniques. The time histories of the accelerations, the displacements, and the impact loads acting on RC beams were recorded, and the cracks from impact loading were observed. The dynamic responses obtained from experiments have been interpreted in detail. The most important issue about plastic hinges was that the hinges do not reach the supports and remain on the beam. This is valid for both hinge support and fixed support. In the second stage of the study, an explicit numerical analysis model, which was verified with experimental results, was developed. The clear agreement between the experimental and numerical results was demonstrated. It has been concluded that proposed finite element procedures can be used for evaluation of the dynamic responses and failure modes of RC beams under low-velocity impact loading. The last part was an analytical study. In this part, the proposed analytical procedure in the previous studies considering the plastic joint formed in a simple support beam under impact loading was confirmed, and a new coefficient for fixed support was proposed. A good agreement has been achieved between analytical and experimental work.

中文翻译：

---

冲击载荷作用下钢筋混凝土梁塑性铰支座型式效应研究

本研究调查了在冲击载荷的影响下，支撑类型对钢筋混凝土 (RC) 梁中塑性铰的影响。在以往的研究中，根据实验、分析和数值结果，对冲击载荷下惯性力线性分布的假设进行了检验和验证。此外，还强调了在冲击载荷下影响 RC 梁行为的最重要参数是塑性铰。计划进行一项三阶段研究来调查这个主题。第一阶段是实验研究。在这部分中，通过使用具有先进测量技术的自由重量测试装置，在具有两种不同冲击能级的低速冲击载荷下测试了四个带有简单和固定支撑的 RC 梁。加速度、位移的时间历程，记录作用在钢筋混凝土梁上的冲击载荷，观察冲击载荷产生的裂纹。从实验中获得的动态响应已被详细解释。塑料铰链最重要的问题是铰链没有到达支撑件而是留在梁上。这对铰链支撑和固定支撑都有效。在研究的第二阶段，开发了一个显式数值分析模型，并通过实验结果进行了验证。证明了实验结果和数值结果之间的明确一致性。已经得出结论，提出的有限元程序可用于评估 RC 梁在低速冲击载荷下的动态响应和破坏模式。最后一部分是分析研究。在这部分，考虑到在冲击载荷下在简单支撑梁中形成的塑性接头，先前研究中提出的分析程序得到证实，并提出了新的固定支撑系数。在分析和实验工作之间取得了很好的一致性。