Papers by Author: Xi Nong Zhang

Abstract: A new method of numerical differentiation and time domain integral was proposed in this paper, its idea was originated from the analysis of the time domain vibration response. As to numerical differentiation, the discrete sequence could be considered as the displacement response of an one degree-of-freedom system, and the velocity and acceleration response corresponding to the first and second order numerical differentiation. As to time domain integral, the discrete sequence could be considered as the acceleration response of an one degree-of-freedom system, and the velocity and displacement response corresponding to the first and second order time domain integral. All these work were established based on the discretization analysis of Duhamel integral. Numerical simulation result indicates the effective and better accuracy of this new method.

Abstract: As an important experiment way adopted in vibration test, response control method obtained more and more attention in recent years, this paper studied the multi-point response control under multi-support excitation in vibration environment test, deduced the transfer equation set between base control excitation and structure response. After analyzing these transfer equation set, the existence and uniqueness of base control excitation was discussed, and proposed an optimization method to solve these transfer equation set based on genetic algorithm (GA). The numerical simulation result indicates the validity of the proposed optimization method. These works provided a theoretical foundation for multi-degree of freedom vibration test in a certain extent.

Abstract: This paper utilizes Genetic Programming(GP) and Genetic Algorithm(GA) to analyze experiment data. The purpose of this research is to establish a function model of the data. The core methodology of this research is using GP to get the approximate model first, and then optimizes the parameters and enhance the fitness value of the model by using GA. To validate this method, two examples are given: one is the reconstruction of permeability-strain equation of the rock in literature[1]; another example is the function search automatically of the wire cable isolator experiment data. In the process of programming of parse tree, this paper adopted a new way that different from three traditional methods, the parse tree is described by matrix of special size, more significantly, this new method makes the genetic operation of crossover and mutation intuitionstic, even the pellucid Matlab programming language could implement it.