Abstract One of the disadvantages of the reduced beam section (RBS) connection is the possibility of lateral-torsional buckling in the beam. Based on previous researches, reducing the cross-section along the web rather than the flange is one of the effective ways to prevent this phenomenon. The authors, in some part of their study on reduced web section (RWS) connections reported in references, have proposed new details about RWS connections by creating an elliptical opening in the beam web and presented recommendations for optimum ranges of the geometrical parameters. The main aim of this paper is to investigate the cyclic performance of an eight-story three-bay welded moment frame having elliptical-shaped RWS (E-RWS) and to compare it with that of the frames having the conventional full- or reduced-beam sections. For this purpose, at first, two connections with the E-RWS and with the common radial-cut (R-RBS) were experimentally tested under the cyclic loading and their performances were examined. The results showed the priority of the E-RWS over the R-RBS in terms of strength, stiffness, ductility, and lateral-torsional stability. Following that, a step-by-step design process for the E-RWS connection was presented. At last, by using an FEM analysis verified by the experimental data, the cyclic performance of an E-RWS frame was compared with that of the full- and RBS frames. According to the results of this study, the creation of an elliptic opening in the beam web can replace the reduced-beam section connections as a suitable method, which can improve the seismic behaviors of MRFs.

中文翻译：

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焊接椭圆形 RWS 力矩框架的循环行为

摘要 减少梁截面 (RBS) 连接的缺点之一是梁中可能发生横向扭转屈曲。根据以往的研究，减少沿腹板而不是翼缘的横截面是防止这种现象的有效方法之一。作者在参考文献中报告的关于减少腹板截面 (RWS) 连接的研究的某些部分中，通过在梁腹板上创建椭圆形开口提出了有关 RWS 连接的新细节，并提出了几何参数最佳范围的建议。本文的主要目的是研究具有椭圆形 RWS (E-RWS) 的八层三间焊接弯矩框架的循环性能，并将其与具有传统全或减径的框架的循环性能进行比较。梁截面。为此，起初，在循环载荷下对 E-RWS 和普通径向切割 (R-RBS) 的两个连接进行了实验测试，并检查了它们的性能。结果表明，在强度、刚度、延展性和横向扭转稳定性方面，E-RWS 优于 R-RBS。随后，介绍了 E-RWS 连接的分步设计过程。最后，通过实验数据验证的有限元分析，将E-RWS 帧的循环性能与全帧和RBS 帧的循环性能进行了比较。根据这项研究的结果，在梁腹板中创建椭圆形开口可以替代缩减梁截面连接作为一种合适的方法，这可以改善 MRF 的抗震性能。