Equivalent dumping coefficient

An equivalent dumping coefficient is a mathematical coefficient used in the calculation of the energy dispersed when a structure moves.<ref>博志, 渡辺; 広隆, 河野 (2000). "L型rc隅角部の強度と変形特性に関する検討". 土木学会論文集. 2000 (662): 59–73. doi:10.2208/jscej.2000.662_59.</ref> As a civil engineering term, it defines the percent of a cycle of oscillation that is absorbed (converted to heat by friction) for the structure or sub-structure under analysis.<ref>Sensors, controls, and quality issues in manufacturing : presented at the Winter Annual Meeting of the American Society of Mechanical Engineers, Atlanta, Georgia, December 1-6, 1991. T. I. Liu, C. H. Menq, N.-H. Chao, American Society of Mechanical Engineers. Winter Annual Meeting, American Society of Mechanical Engineers. Production Engineering Division. New York, N.Y.: ASME. 1991. p. 361. ISBN 0-7918-0840-8. OCLC 26095253.{{cite book}}: CS1 maint: others (link)</ref> Usually it is assumed that the equivalent dumping coefficient is linear, which is to say invariant compare to oscillatory amplitude. Modern seismic studies have shown this not to be a satisfactory assumption for larger civic structures, and have developed sophisticated amplitude and frequency based functions for equivalent dumping coefficient.

When a building moves, the materials it is made from absorb a fraction of the kinetic energy (this is especially true of concrete) due primarily to friction and to viscous or elastomeric resistance which convert motion or kinetic energy to heat.