Inspection Planning of Fatigue Deteriorating Structures Using Genetic Algorithm

Genetic Algorithm (GA) is applied to obtain optimal inspection plan for fatigue deteriorating structures. The optimization problem is defined so as to minimize inspection cost in the life-time of the structure under the constraint of failure probability. Optimization parameters are the inspection timing and the inspection quality. The inspection timing is selected from the discrete intervals such as one year, two years, three years, etc. The inspection quality is selected from the followings ; no inspection, normal inspection, sampling inspection or precise inspection.The applicability of the proposed GA approach is demonstrated through the numerical calculations assuming a single member set and a structure consisting of several member sets. Special elite selection at reproduction and multiple point crossover method are applied to increase the efficiency of optimization. The influence of population size, probability of mutation and probability of crossover on GA are also investigated. Markov Chain Model is employed to calculate fatigue reliability as well as inspection effect. Through the numerical calculations, it is made clear that GA approach is a very useful tool at the optimization of inspection planning.