چكيده به لاتين
By the increasing development of complex and modern structures due to the advancement of science and technology, large investments are being made to bring beauty along with efficiency. Problems arise after a short period of operation of structures, which is a great concern to the builder, the employer and the people who have invested financially. However, an earthquake, a tsunami or a natural disaster or the day-to-day productivity of the structures make them highly susceptible to damage. Researchers conducted several studies to achieve a method for structural health monitoring.
Modal damage detection method for detecting damages with different number and severity is welcomed by researchers and it has been used in this study. The present method falls under the category of model updating. This study presents a new objective function with correlation relationships between flexibility matrix and stiffness matrix, which is trying to identify the damage in a good and accurate manner. An algorithm is used to optimize the response of the objective function and is chosen to produce good convergence. Finally, to prove the efficiency of the new objective function expressed with the selected sine-cosine algorithm, three structures were investigated. These three structures include a 25-bar planar truss, a 26-member bending frame, and a 10-story shear frame. In order to introduce environmental effects, two noise modes were considered, the first one indicates five percent noise at natural frequency and the second one combines 5 percent noise at natural frequency and three percent noise in mode shape. The results show that the maximum error of damage detection in the 25-bar planar truss is 1%, the 26-member bending frame is 3%, and the 10-story shear frame is 2%. These were performed with the SCA algorithm, and finally, in order to evaluate the performance of the proposed optimization algorithm, the expressed objective function was also examined by the particle swarm optimization (PSO) and cuckoo search (CS) algorithm.
