Viscous and Hysteretic Damping - Impact of Capacity Design Violation in Augmented Structural Systems

Type of content
Journal Article
Publisher's DOI/URI
Thesis discipline
Degree name
Publisher
University of Canterbury. Mechanical Engineering
Journal Title
Journal ISSN
Volume Title
Language
Date
2012
Authors
Labise, C.C.
Rodgers, G.W.
MacRae, G.A.
Chase, Geoff
Abstract

Capacity design, while protecting a structure against undesirable energy dissipations, has major implications on member sizes and overall cost. Furthermore, in some situations where protected elements possess some inelastic deformation capacity, it may be unwarranted. One of these situations is when the forces applied to the protected elements result from viscous dampers. This is because when viscous forces cause yielding in an element, the element deforms, so no deformation in the viscous damper is required. If no deformation is required, the velocity is zero, so there is no force. This implies that very little inelastic yielding is likely to occur in protected elements. In order to investigate whether or not this is so, a single storey structure was designed and fitted with braces to reduce its response. Both hysteretic and viscous braces were used to obtain the same peak displacement response. The column strength was decreased by a fixed percentage and inelastic dynamic time history analysis was conducted. The amount of energy dissipated in the columns was then compared to determine whether hysteretic braces or viscous braces caused more column yielding so that appropriate over strength values could be developed for different brace types. It was found that the amount of energy absorbed by the column depends on the period but also on the brace design ductility. However, irrespective of the period or design ductility, the column hysteretic energy dissipated by a viscous brace was lower than that dissipated by a hysteretic brace. It follows that column yielding may be significantly less critical for viscous, rather than for hysteresis, braced structures.

Description
Citation
Labise, C.C., Rodgers, G.W., MacRae, G.A., Chase, J.G. (2012) Viscous and Hysteretic Damping - Impact of Capacity Design Violation in Augmented Structural Systems. Bulletin of the New Zealand Society for Earthquake Engineering, 45(1), pp. 23-30.
Keywords
supplemental damping, earthquake engineering, structural design, inelastic deformation, viscous damping, hysteretic damping
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Fields of Research::40 - Engineering::4005 - Civil engineering::400506 - Earthquake engineering
Fields of Research::40 - Engineering::4005 - Civil engineering::400510 - Structural engineering
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