Application of a New Cylindrical Slit Damper for Mitigation of Structural Vibrations

Authors

Faculty of Civil Engineering, University of Urmia

Abstract

     This study introduces a new kind of steel slit damper which can be installed diagonally in steel frames as a brace-type vibration damper. This new damper consists of three standard cylindrical tubes which have been placed inside of each other. On the middle tube wall, several long slotted holes are created in a manner that under seismic excitation, axial forces are created in the braces and then by its transmission to the tubes, narrow strips between these long slotted holes are yielded and therefore energy is dissipated through shear/flexural yielding. The inner and the external tubes will prevent the out of plane deformation of the middle tube. For fixing these tubes to each other and limiting the forward and backward movement of the middle tube, two long slotted holes have been created on the tubes walls. In comparison to the other available brace-type dampers, such as buckling restrained brace, this damper is simpler and costs less. The yielding part of this modified damper can be easily inspected after an earthquake. This damper was analyzed in ABAQUS and its hysteresis curve and the effects of its mechanical characteristics such as strip length, strip depth, strip thickness were obtained. For checking the effectiveness of device in mitigation of structural responses, the model of a 5-story frame, which was already designed under Iranian 2800 seismic code, was created in SAP2000. Then this structure, with and without damper was analyzed under different ground motions such as Tabas, Kobe and Elcentro. The results were indicating that the lateral displacements and the base shears of the multi-story building have been significantly reduced

Keywords


[1]    FEMA273, NEHRP, "Guidelines for Seismic Rehabilitation of Buildings", Prepared by the Building Seismic Safety Council for Federal Emergency Management Agency, Washington DC, US, 1997.
[2]    Sarnoand, I. D., Elnashai, A. S., "Seismic Retrofitting of Steel and Composite Building Structures", University of Illinoise, US, 2002.
[3]    Oh, S. H., Kim Y. J., Ryu, H. S., "Seismic Performance of Steel Structures with Slit Dampers", Engineering Structures, 2009, 31, 1997-2008.
[4]    Lee, M. H., Oh, S. H., Huh, C., Oh, Y. S., Yoon, M. H., Moon, T. S., "Ultimate Energy Absorption Capacity of Steel Plate Slit Dampers Subjected to Shear Force", Steel Structures, 2002, 2, 71-79.
[5]    Ricky, W. K., Chan, F. A., "Experimental Study of Steel Slit Damper for Passive Energy Dissipation", Engineering Structures, 2008, 30, 1058-1066.
[6]    Takeuchi, T., Hajjar, F. J., Matsui, R., Nishimoto, K., Aiken, D. I., "Effect of Local Buckling Core Plate Restraint in Buckling Restrained Braces", Engineering Structures, 2012, 44, 304-311.
[7]    Tremblay, R., Bolduc, P., Neville, R., Devall, R., "Seismic Testing and Performance of Buckling-Restrained Bracing Systems", Canadian Journal Civil Engineering, 2006, 33 (2), 183-198.
[8]    Morino, S., Kawaguchi, J., Shimokawa, H., "Hysteretic Behavior of Flat-Bar Braces", International Conference on Advances in Steel Structures, Hong Kong, 1996, pp 1127-1132.
[9]    Iwata, M., Kato, T., Wada, A., "Buckling-Restrained Braces as Hysteric Dampers", The Behavior of Steel Structures in Seismic Areas STESSA, Montreal, Canada, 2000, pp 33-38.
[10]  Benavent, A., "A Brace-Type Seismic Damper Based on Yielding the Walls of Hollow Structural Sections", Engineering Structure, 2010, 32, 1113-1122.
[11]  Hibbitt, Karlsson and Sorensen, Inc., "ABAQUS/Standard User’s Manual". Pawtuckett (RI), US, 2002.
[12]  Computers and Structures, Inc., "SAP2000 User’s Manual", Berkeley (CA), US, 2003.