The Moment-Independent Importance Analysis of Structural Seismic Requirements Based on Orthogonal Polynomial Estimation

Abstract

The structural damping ratio, structural quality, yield strength, and elastic modulus of section steel, compressive strength, elastic modulus of concrete, yield strength, and elastic modulus of steel bars play important roles in the stability of the steel-reinforced concrete (SRC) frame structure, which are usually uncertain. However, their importance influence on the different seismic demands of SRC is rarely investigated simultaneously. In order to investigate the effects of the above parameters on four seismic demands (i.e., the top displacement, the maximum floor acceleration, the base shear force, and the maximum interstory displacement angle) of SRC frame structures, the orthogonal polynomial estimation method is first applied to the importance analysis of structural seismic demand based on the moment-independent method. Two engineering examples are performed to verify the accuracy and efficiency of the proposed method. The results have the characteristics of fast convergence and are in good agreement with those obtained by the moment-independent method based on kernel density estimation. The variance importance index based on Monte Carlo (MC) method is also calculated for comparison. The influence of each random variable on the four structural seismic demands is basically the same. Therefore, the accuracy and efficiency of the proposed method are proved sufficiently.

Importance Analysis of Structural Seismic Demand Based on Support Vector Machine

“…e analysis of the in uence of random variables on the seismic demand of structures belongs to the uncertainty analysis [3]. ere are many research methods for the uncertainty analysis [5,6], in which the sensitivity analysis of random variables is the prevailing method for the uncertainty analysis [7,8]. It is well known that the sensitivity analysis includes two common methods, which are the local sensitivity analysis (LSA) and the global sensitivity analysis (GSA, also known as importance analysis), respectively [9].…”

Efficient Moment-Independent Sensitivity Analysis of Uncertainties in Seismic Demand of Bridges Based on a Novel Four-Point-Estimate Method

“…Song et al applied the MII and variance importance methods to analyse the sensitivity of uncertain parameters involved in the seismic demands of bridge structures by MC simulations and kernel density estimation, respectively [11]. Xu and Wang applied the Sobol sequence instead of MC methods to simulate the samples of eight uncertain parameters and the orthogonal polynomial estimation method to obtain the MII measures on four seismic demands of steel-reinforced concrete frame structures [12]. The aforementioned studies on the global sensitivity analysis of uncertain parameters to seismic demands are based on sampling-based methods such as MC simulation or Sobol sequences, which require a large number of NTHA of structural models because the global sensitivity index evaluation involves a double loop simulation to propagate the uncertainties for evaluation of the unconditional and the conditional probability density function (PDF) of seismic demands.…”