Inherent Damping in Nonlinear Time-History Analyses: A Recommended Modelling Approach

In a nonlinear dynamic analysis, the most popular way of representing the inherent damping exhibited by the structure is by adopting the classical Rayleigh damping model. Although a large number of studies have identified issues with this model, it remains the most popular choice in the currently available non-linear time-history analysis software. A new paradigm for modelling damping was proposed by the authors in Puthanpurayil AM, Lavan O, Carr AJ, Dhakal RP (Bull Earthq Eng 14:2405-2434, 2016) and is summarised in this chapter. This new model provides for the damping effects at an elemental level. The chapter outlines the performance of the elemental damping models in comparison to the classical global damping models by conducting Incremental Dynamic Analyses (IDA) on a four-storey RC frame designed to Eurocodes. The IDA study presented in the chapter illustrates the fact that the elemental damping models give a more reliable estimate for the structural responses in comparison to all other models.