PARAMETRIC STUDY TO ASSESS BUILDING NONLINEARITY INFLUENCE ON SEISMIC RESPONSE OF NONSTRUCTURAL COMPONENTS

An extensive parametric study is conducted to investigate how the nonlinear behavior of a building affects the seismic response of nonstructural components attached to it. The study comprises the timehistory analysis of a series of single-degree-of-freedom nonstructural components alternatively attached to eight code-designed steel moment-resisting frames. In each case, the analysis is conducted under an ensemble of 25 recorded ground motions selected from a suite of 84 records, alternatively scaling them to three different intensity levels. In each case, too, a comparison is made between the nonstructural component responses obtained when in the analysis the supporting structure is modeled alternatively as a linear and a nonlinear system. The influence of the relative values of the natural frequencies of building and nonstructural component, nonstructural component location within the building, and nonstructural component nonlinearity is also investigated. It is found that nonlinearity of the supporting building may significantly amplify the seismic response of a nonstructural component if (a) the component is attached to one of the lower floors of the building, (b) its fundamental natural period is close to the second or third natural period of the building, and (c) the building is subjected to a narrow-band excitation with a dominant period close to the building’s fundamental natural period.