Correlation Between Loading Rate, Temperature Rise, and Material Properties Changes in Plastic Rotation Capacity of Steel Welded Beam-to-Column Connections

钢焊接梁柱连接塑性旋转能力的加载速率、温升和材料特性变化之间的相关性

基本信息

批准号：
12450224
负责人：
NAKASHIMA Masayoshi
金额：
$ 5.63万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

This study focuses on the quantification of complex interaction between loading rate, temperature rise, and material's property changes regarding the plastic rotation capacity of steel welded beam-to-column connections.The background of this study is the possible linkage, starting from dynamic loading, energy dissipated by plastificatiori, conversion of the dissipated energy to thermal energy, temperature rise due to thermal energy, change in material's toughness caused by the temperature rise, change in material's ductility, and eventual change in plastic rotation capacity of connections. To this end, dynamic loading tests applied to real-scale beam-to-column subassemblages, detailed nonlinear finite element analysis, and numerical heat conduction analysis were conducted, and the following findings were obtained.(1) Cumulative plastic strains and temperature-rise are correlated strongly ; the classical hypothesis that the plane section remains plane is not applicable in the proximity … More of beam end ; and vertical stiffeners arranged to avoid local buckling also altered the local strain distributions.(2) Detailed nonlinear finite element analysis supported the experimental findings, and it was found that the primary reasons for complexity of strain distributions are the flexibility of column flange (in its out-of-plane bending) and the existence of weld access holes.(3) The heat conduction analysis indicated that heat convection to air is negligible in the loading rate expected during earthquakes but that heat transfer within the steel material is conspicuous. The analysis also verified that the temperature rise in the very proximity of beam end is smaller than the temperature rise in regions slightly away from the end, and it is due to the existence of the non-plastified column attached to the beam end.(4) Proposed also was a procedure to estimate the thermal energy distributions (i.e., the cumulative plastic strain distribution) from the measurement of temperatures at discrete locations. This procedure is to provide a new, reliable measuring index for the purpose of structural health monitoring. Less

这项研究的重点是负载速率，温度升高和材料性质之间关于钢焊接旋转能力的变化之间的复杂相互作用的数量连接的塑料旋转能力的变化。为此，进行了动态载荷测试，应用于实尺度的光束至列子汇编，详细的非线性有限元分析和数值热传导分析，并获得了以下发现。（1）累积塑性菌株和温度 - 温度 - 温度 - 温度 - 温度 - 温度 - 温度降低相关;平面截面保持平面的经典假设不适用于接近……更多的光束端。安排避免局部屈曲的垂直压力剂也改变了局部应变分布。（2）详细的非线性有限元分析支持了实验发现，发现应变分布的复杂性的主要原因是柱状法兰的灵活性（在平面外弯曲中的灵活性）（其平面外弯曲）以及在焊接孔中的存在指示的热管率指示了热管率的降温率。钢材材料中的热传递是显着的。 The analysis also verified that the temperature rise in the very proximity of beam end is smaller than the temperature rise in regions slightly away from the end, and it is due to the existence of the non-plastified column attached to the beam end.(4) Proposed also was a procedure to estimate the thermal energy distributions (i.e., The cumulative plastic strain distribution) from the measurement of temperatures at discrete locations.此程序是为了进行结构健康监测的目的，提供了一个新的可靠测量指数。较少的