Nonlinear dynamic analysis method for large-scale single-layer lattice domes with uncertain-but-bounded parameters

Abstract

Most of current evaluations for structural design are based on deterministic analysis. In practice, the parameters of the structure such as material, mass distribution, imperfections and damping have uncertainties. this will affect the final evaluations and structural safety if the deterministic analysis method is still used. The conventional method has to be improved. Therefore, there is an increasing need for evaluating the structural performance with the uncertainty analysis method. In this study, a method is developed and presented for the dynamic uncertainty analysis of a large-scale single-layer lattice dome. The method can take into account the uncertainties of the damping, the material, the structural mass or load, and the geometry imperfections of the structural shape and all members. It is implemented by assuming that the variability of each random input parameter with respect to the ideal parameters of the perfect structure obeys a mathematical distribution. Specifically, there is a basic difference between the present study and other related studies on treatments of uncertainty in damping. After a computer model of the dome with the geometry imperfections of the structural shape and all members is constructed, finite element dynamic analyses with uncertainties of damping and input parameters are performed. Additionally, the mathematical distributions of dynamic properties and demands are analyzed. Results show that the variability of the parameters with an associated uncertainty imposes significant negative effects on the dynamic performance of the dome, and the probability of failure of the dome increases as increase of variability levels of uncertain parameters, indicating that reducing the uncertainty of the input parameters has a significant contribution to the safety of a dome. By comparison, a significant difference in the dynamic demands is observed when the uncertainty analysis method and conventional analytical method are respectively used for the dynamic analysis; the numerical results reveal the necessity for the use of the proposed method in practical applications.

Dynamic Characteristics of Reticulated Domes Built of Composite Elastic/Viscoelastic Rods Modeled by the Fractional Zener Model

“…The optimization of dome structures with dynamic constraints is presented in [23,24], while, in [25], the dynamic analysis and seismic design method for reticulated domes with semi-rigid joints are discussed. Recently, an interesting nonlinear dynamic analysis of lattice domes was presented in [26], where the uncertainty of structural parameters is taken into account. Very recently, the dynamic reliability analysis of super large lattice domes was presented in [27].…”