The Studies Of Sensor Placement And Damage Detection For Offshore Platform Based On Genetic Algorithm

This paper discusses the development and the methods of sensor placement and damage detection, and the basic theory and the characteristic of genetic algorithm. It focuses on the sensor placement and the damage detection of offshore platforms.Two optimal principles of sensor placement, Modal Assurance Criterion (MAC) and Displacement Energy, have been discussed based on the relativity of modes and the displacement energy. Updated cumulative method, which optimize the objective by cumulating directly all the freedoms left by QR decompose according to their contribution to the objective, has been proposed. Reduced Method has been proposed based on the principle of reducing the freedom affecting the objective the most. It is suggested that both optimal result and economy must be considered in a sensor placement; Applies genetic algorithm to the sensor placement and presents dualistic coding genetic algorithm aiming at restriction problem in genetic operation; Comparing the results getting from partial and global optimal methods proves superiority of genetic algorithm and presents each sensor placement schemes of offshore platforms.Taking natural frequency and mode as damage principle, damage detection is studied as optimal problem based on genetic algorithm, and damage indices, symmetry and precision in the damage detection is discussed. Numerical simulation of the damage detection of offshore platforms using genetic algorithm proves the feasibility of genetic algorithm in damage detection of large structure; Program all the process of geneticalgorithm in damage detection into damage detection system.