Testing a Repairable Lateral Resisting System Applied To Braced Steel Frames


Abstract eng:
A seismic upgrading technique using the steel ring connection (SRC) was presented to enhance the lateral ductility, energydissipation and damping potential of the existing frame systems. The SRC system performed as a repairable energydissipating device and was used with X-braces in the steel frames. Experimental studies were conducted on SRC system to evaluate the performance of the proposed system for upgrading the behavior of the steel frames. The proposed technique consisted of the X-bracing system with a steel ring element at the mid-point connection. The lateral load on the frame was allowed to transfer to the steel ring element through the braces. The lateral displacement of the braced frame caused yielding of the SRC in bending deformation mechanism and dissipated energy due to forming of plastic hinges in the ring in reversed cyclic deformations. No extensive retrofitting of the existing frame members was required for the proposed technique. In order to investigate the effectiveness of the proposed system on the cyclic response of the frame and study of performance of the SRC as energy-dissipating device, a series of quasi static cyclic tests were conducted on a full-scale single storey steel frame. The frame was upgraded with proposed system consisting of X-braces and the SRC. Two types of braces were used and studied for the proposed system: 1) Tension only rods which caused the SRC laterally deformed in tension in each half cycle, and 2) Hollow section tube (tubular brace) which made the SRC deformed in both tension and compression periodically in each cycle. A benchmark test was carried out on each brace type with no SRC (regular braced frame). Hysteretic load-deformation response, lateral strength, stiffness, equivalent effective damping and dissipated energy in reversed cyclic motions were compared for the upgraded braced frame and the regular system in both brace types. The upgraded braced frames with SRC exhibited enhanced energy-dissipation and damping potential as compared to the regular system. SRC system showed more stable hysteresis loops than the regular braced frames. This experimental study confirmed that the SRC is an excellent energy-dissipation device and the proposed technique is a suitable concept for use in the existing buildings to reduce the damage level in the frame members in high-risk seismic zones.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 2440.:
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