دانلود رایگان ترجمه مقاله عملکرد لرزه ایی اتصالات ممان فولاد مقطع کاهش یافته (نشریه asce 2005)

اثرات استحکام ناحیه پانل و روش اتصال شبکه ایی پرتو: عملکرد لرزه ایی اتصالات ممان فولاد مقطع کاهش یافته

Effects Of Panel Zone Strength And Beam Web Connection Method: Seismic Performance Of Reduced Beam Section Steel Moment Connections

SUMMARY

This paper presents test results on eight reduced beam section (RBS) steel moment connections. The testing program addressed bolted versus welded web connection and panel zone (PZ) strength as key variables. Specimens with medium PZ strength were designed to promote energy dissipation from both PZ and RBS regions such that the requirement for expensive doubler plates could be reduced. Both strong and medium PZ specimens with a welded web connection were able to provide satisfactory connection rotation capacity for special moment-resisting frames. Specimens with a bolted web connection performed poorly due to premature brittle fracture of the beam flange at the weld access hole. If fracture within the beam flange groove weld was avoided using quality welding, the fracture tended to move into the beam flange base metal at the weld access hole. The measured strain data showed that the classical beam theory dose not provide reliable shear transfer prediction in the connection. Criteria for a balanced PZ strength that improves the plastic rotation capacity while reduces the amount of beam distortion are also proposed.

۱ Introduction

As a response to the widespread damage in connections of steel moment-resisting frames that occurred during the 1994 Northridge, California and the 1995 Kobe, Japan earthquakes, a number of improved beam-to-column connection design strategies have been proposed. Of a variety of new designs, the reduced beam section (RBS) connection has been shown to exhibit satisfactory levels of ductility in numerous tests and has found broad acceptance in a relatively short time (Chen 1996; Plumier 1997; Zekioglu et al. 1997; Engelhardt et al. 1998). In the RBS connection a portion of the beam flanges at some distance from the column face is strategically removed to promote stable yielding at the reduced section and to effectively protect the more vulnerable welded joints. This weakening strategy also reduces the seismic force demand on the column and the panel zone. Although this type of moment connection has been widely used in the past few years, there remain several design issues that should be further examined (for example, Jones et al. 2002; Gilton and Uang 2002; Chi and Uang 2002). The primary objective of this experimental study was to investigate the effects of beam web connection type and panel zone strength on the seismic performance of RBS connections