Papers by Author: Cheng Su

Abstract: A model is proposed to simulate multivariate weakly stationary Gaussian stochastic processes based on the spectral representation theorem. In this model, the amplitude, phase angle, and frequency involved in the harmonic function are random so that the generated samples are real stochastic processes. Three algorithms are then adopted to improve the simulation efficiency. A uniform cubic B-spline interpolation method is employed to fit the target factorized power spectral density function curves. A recursive algorithm for the Cholesky factorization is utilized to decompose the cross-power spectral density matrices. Some redundant cosine terms are cut off to decrease the computation quantity of superposition. Finally, an example involving simulation of turbulent wind velocity fluctuations is given to validate the capability and accuracy of the proposed model as well as the efficiency of the optimal algorithms.

Abstract: Applying similarity theory to study the characteristics of scale model for getting agreement between scale model test and prototype test. On the basis of the theoretical analysis of scale model test, a formula derivation of similarity condition was carried out based on similarity theory. A numerical example for joint of steel beam to CFST (concrete-filled steel tubular) was given to show the accuracy formula of similarity condition. The result showed that error results from non-full-similar geometrical properties was considerable between poorly-proportioned model test and prototype. For getting good agreement between scale model test and prototype test, the well-proportioned model should be calculated by the formula of similarity condition for the joint of beam to column.

Abstract: This paper deals with probabilistic sensitivity analysis for a semi-rigid joint of continuous web plate based on correlations analysis. Firstly, a numerical study was carried out by the software package ANSYS, the finite element analysis was validated compared with experimental results. Secondly, parameters sensitivity analysis was carried on by applying ANSYS Probabilistic Design Analysis. Considering the correlations in primary parameters, all random parameters are varied at the same time based on Monte Carlo simulation. An especial expression between geometric parameters and moment-rotation was discussed. Thirdly, the moment-rotation model of the joint was attained. The composite constant of the moment-rotation model is determined by partial derivative of any parameter from the model. It is concluded that the parameters of the model have notable physical meaning and the proposed model should be accurate and acceptable.

Abstract: In traditional semi-rigid analysis of extended end plate connections is assumed to be deterministic parameters, most of moment-rotation models of the joint is determined by curve-fitting and statistically regressed with the test data. Those parameters of the models have little physical meanings and the effect of correlations between parameters is neglected. This paper deals with a semi-rigid joint of extended end plate connections based on correlation and sensitivity analysis. A numerical study was carried out and the finite element analysis was validated compared with the experimental results.The relative moment-rotation model was concluded based on correlations in parameters and probabilistic sentivity analysis. The relationship between height and width of steel beam was partial correlation, the relationship between thickness of steel beam flange and thickness of steel beam web was partial correlation. Height and width of steel beam, the distance of upper bolts to axle wire of steel beam were important sensitive parameters for the extended end plate connections.