Re-evaluation of Conventional Seismic Beam-to-Column Flange Steel Connection

9416457 Popov在该项目中对钢梁柱节点进行了协调研究。 研究将集中在焊接和连接的基本问题。 本文将对部分子组合进行试验研究：1。 支撑杆的作用。 通过对支撑钢筋进行试验，以及将这些钢筋拆除并清理焊缝根部并重新焊接，将记录性能改善的程度。 2. 全熔透坡口焊缝端部的挡料板和溢流片的影响。 一些实验说明这种水坝与径流片的影响将是有价值的。 3. FCAW一般采用高熔敷电极。 尽管FCAW高熔敷焊条几乎被普遍使用，但使用GMAW（焊条）的实验室经验通常显示出更好的结果。 4. 预热和控制冷却对接头完整性的贡献。 超过或违反AWS准则的情况将表明对此参数的敏感性。 5. 尺寸对关节完整性的影响。 在北岭地震中的许多失效节点中，钢构件的尺寸由于对长净跨的需求而非常大。 6. 改进了大尺寸连接的细节。 将研究一些可能的细节，以加强这种节点，迫使临界塑性铰远离柱的表面。 考虑对不同尺寸的几个试样进行测试。 这可能包括带有混凝土板的样本。 能力分析将用于确定构件尺寸以及制定设计要求。 7. 残余应力分布 残余应力以及由恒载和活载（地震）施加的应力，这些应力可能导致在受损区域的钢建筑物接头中反复观察到的失效类型。 8. 悬臂梁-柱子组件。 计划制造和测试两个传统的梁柱子组件。 9. 两侧的悬臂柱。 由于经费有限，只考虑制作一个标本。 本试验的主要目的是研究面板区域以及梁连接。 该项目与圣地亚哥的加州大学和奥斯汀的得克萨斯大学的伙伴项目协调进行。 这是一个北岭地震项目。 ***

9416457 Popov A coordinated research effort on steel beam-to-column joints is conducted in this project. The study will concentrate on the fundamental problems of welding and connections. Some subassemblages will be tested to study: 1. The effect of backing bars. By experiments with backing bars and with such bars removed and weld roots cleaned and rewelded, the extent of improvement in behavior would be documented. 2. The effect of dams and run-off tabs at the ends of full- penetration groove welds. A few experiments illustrating the influence of such dams versus run-off tabs would be valuable. 3. The general use of FCAW high deposition electrodes. Although the FCAW high deposition electrodes are almost universally used, laboratory experience using GMAW (stick) often shows better results. 4. The contribution of preheat and controlled cooling to the integrity of joints. Cases where AWS guidelines are exceeded or violated would indicate sensitivity to this parameter. 5. The effect of size on joint integrity. In many of the failed joints during the Northridge Earthquake, steel member sizes, driven by desire for long clear spans, were very large. 6. Improved details for large-size connections. Some possible details will be studied for enhancing such joints by forcing the critical plastic hinge away from the face of the column. Testing of several specimens of different size is contemplated. This may include specimens with concrete slabs. Capacity analyses will be used in establishing member sizes, as well as in developing design requirements. 7. Residual Stress Distribution. The residual stresses together with those imposed by dead and live (earthquake) loads that can cause failures of the type repeatedly observed in steel building joints in the damaged area. 8. Cantilever Beam-Column Subassemblages. It is planned to fabricate and test two conventional beam-column subassemblages. 9. Cantilevers on Both Sides of Col umn. Due to limitation of the funds, only a single specimen is contemplated. The main purpose of this test is to study the panel zone, as well as beam connections. This project is coordinated with companion projects at the University of California at San Diego and at the University of Texas at Austin. This is a Northridge Earthquake project. ***