Dimensional pounding response analysis for adjacent inelastic MDOF structures based on modified Kelvin model

Abstract

The dimensional analysis method is used to study the pounding response of two inelastic MDOF (multi-degree-offreedom) structures under simplified earthquake excitation. The improved Kelvin pounding model is adopted to simulate the force and deformation of the collisions during the contact process. The bilinear interstory resistance model is used to describe the inelastic characteristics of the MDOF structures. The expression of dimensionless pounding force and the equation of dimensionless motion during the collision process are derived. Based on the above theoretical derivation, the accuracy of the improved Kelvin model is verified by comparing the pounding responses in the form of spectra between the improved Kelvin model and Kelvin model. The effects of the pounding on the response of the left structure (with a smaller mass and stiffness) are analyzed in different trend (amplification region, suppression region and unaffected region), and the self-similarity of the pounding response for the two inelastic MDOF structures is revealed. The effects of the story mass ratio, post-yield stiffness ratio, yield displacement and structure spacing on the pounding response are studied. The peak displacement response of the left side structure increases with the increasing of story mass ratio and decreases with the increasing of yield displacement and postyield stiffness ratio. With the increasing of structure spacing, the peak displacement decreases in the first spectrum region, and in the second spectrum region, the peak displacement increases. Moreover, the change of the parameters has little effect on the response of the right structure (with a larger mass and stiffness).