Improved Genetic Algorithm And Its Application And Research In Structural Engineering Optimization

Genetic Algorithm (GA), a method of bionics algorithms simulating evolution theories of biology, is widely applied in engineering optimization and other scientific computation fields. In this dissertation the genetic algorithm research progress in recent years and related references were summarized and studied in the design of structural optimization. Author discussed and analyzed the basic theory, the method characteristics of Genetic Algorithm in the design of structural optimization. The main work as followed: 1. Improved and debugged the optimal program based upon the simple genetic algorithm. The examples of trussed structure system optimization show that the program is feasible and valid. 2.Presented the improving measures pertinent to simple genetic algorithm (SGA) of low searching efficiency and premature, including (1) adopt niche technique, crossover operator for binary coding;(2) the competitive elitist model is proposed, in virtue of thought that the natural life of individual is usually long among biosphere. The test results show that the improved genetic algorithm (IGA) has better adaptability and stability than the SGA, no matter which type of optimization problem continuous or discrete, linear or nonlinear, and constrained or free. 3. Based on IGA, built up the computing model with objective function in the smallest weight of the truss structure and developed the structure optimal program. The running out showed that the IGA has the excellent convergence and computing rate. 4. IGA was introduced to solve the theory problem for reinforce concrete truss structure with open webs. Built up the computing model with objective function in the minimum fabrication cost of the crossbeam and post of the truss structure and run the structure optimal program. The optimal results have a good agreement with adopting numerical values in engineering. So it is shown that it is successful in applying the IGA to optimize the R.C. truss structure with open webs. The optimal outcome of this dissertation is able to guide engineer to make a rational decision on designing the R.C.