An Improved Genetic Algorithm And Its Application In Optimal Configuration Of Dampers

Genetic algorithm is an intelligent optimization algorithm with strong robustness,the process of it not required the gradient information of objective function,so it is widely used to solve engineering optimization problems.However,as a random searching algorithm,genetic algorithm would get global optimum solution of optimization problem in need of multiple iterations for objective function.Consequently,slower convergence speed(compared with gradient algorithm),low-fidelity and premature exist in the process of genetic algorithm inevitably.Accordingly,it has become a hot research area currently to improve the global and local strategy of genetic algorithm for solving optimization problems in specific projects.The optimal installation of dampers in a high-rise structure can be solved by genetic algorithm.But it is quite difficult even anable to solve problems by the traditional standard genetic algorithm when the number of dampers is very large,the number of dampers installed on each floor is different or it’s need to optimize the placement and performance parameters of dampers at the same time.To cure the above problems,the main aspects of this paper are as follows:Firstly,construct the relative fitness genetic algorithm with relative fitness selection operator.Use this algorithm to optimize the installation of dampers of a 22-story frame structure model and to compare with the standard genetic algorithms with elitist model.It is concluded that relative fitness selection operator can make the most use of the fitness differences of chromosomes in a population and accelerate the evolution,then obtain the global optimal solution of optimization problem.Secondly,in view of the situation that the number of dampers installed on each floor is different,the digital sequence coding is designed to express the solution space of optimization problem,making it have sufficient completeness and legitimacy,then get a good Lamarckian property and strong causality.Corresponding to this coding scheme,the discrete-recombination cross operator was designed to ensure the effective evolutionary of the population.The placement of the dampers in a 16-story frame structure model was optimized by this improved genetic algorithm.Under the action of multiple seismic waves,several response control indices and different combination modes of these indices are considered in this model.considering,and then normalization processing was carried out on the objective function.Finally,to solve the complex optimization problem that considering the placement and performance parameters of dampers at the same time,the hybrid coding genetic algorithm was put forward which constructs the corresponding special genetic operators.The installation of dampers was optimized in a 12-story and a 16-story frame structure model by the hybrid coding genetic algorithm.The calculation results show the validity and availability of the hybrid coding genetic algorithm.