معرفي الگوريتم مناسب كنترل فعال براي كاهش اثرات ناشي از زلزله هاي نزديك گسل در پل هاي بزرگراه

Introducing an appropriate active control algorithm for the reduction of the destruction caused by near- field earthquakes in highway bridges

The ground motion of near-field earthquakes is characterized by a high peak acceleration and a velocity pulse with a long period component as well as a large displacement. In this article, the application of the concept of active control for the reduction of the destruction caused by near-field earthquakes in brigde benchmark structures is investigated. In this vein, artificial neural network and fuzzy logic and combination of artificial neural network and fuzzy logic for the design of active algorithm are used. The most significant advantages of fuzzy controller are inherent stability and capacity for the survey of the non - linear behavior of the structures. The fuzzy logic used in this article uses directly crisp data derived from sensors. This data is converted to fuzzy language or the membership functions during the fuzzification process. In addition to the fuzzy logic procedure in the present article, a back-propagation algorithm based on artificial neural networks is also used. A step-by-step non-linear analysis is done using new-mark-B, and for better representation of the non-linear behavior, a bilinear hysteresis model is used to model plastic hinge. In this article, for the evaluation of the designed control algorithm efficiency, some near-field records are used. These records consist of seventeen (17) evaluation criteria and are compared using LQG style. The evaluation criteria used are divided to four categories: 1) Structural responses 2) Structural damage 3) Control devices 4) Control strategic requirements The comparison of the results obtained in case of evaluation criteria of active control algorithm designed in this article and LQG style, firstly was the transformation shown in the appropriate algorithm for near- field and far-field earthquakes and secondly it is assumed that the active control algorithm designed with the fuzzy logic is the most appropriate algorithm for the reduction of the destruction caused by near-field earthquakes.