Nonlinear Material Loss Factors of Single-Layer Latticed Domes Subjected to Earthquake Ground Motions

The quantification of damping in a structure is of significant interest in structural dynamics. At present, there is still no clear consensus on how damping issues are resolved. Although the Rayleigh damping model, which combines mass-proportional and stiffness-proportional parts, leads to reasonable engineering demand parameters of a structure within its elastic range, it does not include nonlinear response history analysis. On the other hand, a great deal of material tests demonstrate that most metallic materials under cyclic loading exhibit a stress-strain relationship that is not elastic even at stresses well below the yield point, however, the material damping effect is seldom taken into account in dynamic analysis. The present study proposes an approach that explicitly considers the additional material damping effect based on Goodman's theory on energy dissipation of materials. The approach is applied to the nonlinear dynamic analyses of single-layer latticed domes subjected to earthquake ground motions. Parametric studies are carried out to evaluate the structural material loss factors under different seismic hazard levels. Finally, a comparative study of the effect of material damping on dynamic responses is discussed. The objective of this study is to quantify the structural material loss factors and to obtain reasonable dynamic seismic demands by means of the easy-to-apply numerical procedure proposed in this paper.