Based On The Improved Genetic Algorithm Structure Reliability Calculation

Engineering structure usually involves many structures, including civil architecture and industrial buildings, the structure of the main types steel structure and wood, brick structure, concrete, steel reinforced concrete structure. In the structure of the use of the structure under load during a permanent load and variable load and accidental load. Permanent load is divided into the structure of its own gravity, soil pressure, pretested load, and so on, including variable load floor live load, crane load and wind load, snow load, the accidental explosion, the shock load has. and so on. In addition to inherit all kinds of load structure besides get the outside indirect effect, indirect effect and concrete’s shrinkage, the change of the temperature, the basis of uneven settlement, earthquakes, etc. A project safety, not only affects people’s life safety, but also relates to the social development, especially those who can represent a time of the cultural characteristics of the structure, will pay more attention to safety, durability, applicability.At present, the reliability analysis of numerical calculation of a first order second moment method, the geometric method, the response surface method. Monte carol method several main calculation method. This paper will be a heuristic genetic algorithm global stochastic search optimization method is applied to structure analysis.Genetic algorithm is one kind of organic and adaptive random searching algorithm that simulates the evolution process and mechanism in nature to solve the optimization problems. It express the process of solving a problem as the process of survival of the fittest of the chromosome using for reference the idea of "survive the superior and eliminate the inferior, survival of the fittest" in Darwin’s nature selection and the genetic mutation theory of Mendel. It makes the population search the best acclimation individual by the incessant evolution to the chromosomes. including the selection operator, the crossover operator, the mutation operator and so on. and then gain the optimal solution or satisfactory solution.As an optimization technique, genetic algorithm has no exacting terms for objective function and constraint condition, by virtue of the MATLAB-based genetic algorithm toolbox programmed by Sheffield University, this paper does research on the reliabilities for provided performance functions and a truss structure taking into account uncertain multifactor. and it has an good effect. In this paper, the genetic algorithms is used for solving the structure reliability, form the search of the restrictive assumption constraints.not the objective function is continuous, differentiable hypothesis,the consequence of genetic algorithms compared with the method of JC. and display the genetic algorithms in the structure reliability in the calculation of the advantages. It gives a new idea and a new way to the structure reliability analysis.