Study On The Equipment-structure System Considering The Effect Of Frequency Ratio And Shaking Table Test

Research shows that the equipment and the structure are working together under action of earthquake,there is complex dynamic interaction between two of them,thus forming the equipment-structure system.In practical engineering,different equipment has its own unique natural frequencies.The interaction force between the equipment and the structure under different frequency ratios will inevitably affect the dynamic response of the equipment and structure.The shaking table test was carried out on the four-story steel frame structure model with 1/5 scale factor.In this paper,the effect of equipment-structure Frequency ratio(?)on the dynamic response of equipment-structure system is studied based on the shaking table test,then some laws related to frequency ratio(?)are summed up,and some corresponding suggestions are put forward for engineering related problems,all of this provide a reference for the seismic design of equipment-structure coupling system.The main contents of this paper and related research results are as follows:(1)The author participated in the large-scale shaking table test,which was carried out in the State Key Laboratory of Structural Engineering,Beijing University of Technology.The test scheme and test model are designed and implemented.The test equipment and instruments,arrangement of sensors and strain gauges,seismic wave selection as well as loading system and other preparatory work were carried out.(2)Shaking table test of equipment-structure system was carried out under Tianjin,El Centro and Artificial earthquake ground motions small and medium earthquakes conditions and so on.Then the displacement and acceleration signal test data of the top floor center of structure and equipment vertex was obtained.In this paper,ANSYS finite element calculation of the test model is carried out,then the correctness of finite element model is validated.(3)In order to extend analysis,the test finite element model is converted to prototype finite element model based on the similarity theory,then Kobe,El Centro and Artificial earthquake ground motions are selected,after that the dynamic response laws of equipment-structure system in case of different equipment-structure frequency ratio are studied,the related research results and conclusions are as follows: The region(0.5(27)?(27)1.5)is a resonance sensitive region,in this region,the dynamic response of the structure is reduced,while the dynamic response of the equipment increase significantly and reach the peak value in the near region(?(28)1);In the region(?(29)3.5),the effect of dynamic interaction force on the dynamic response of equipment and structure is very small.There are few differences between the results calculated by the decoupling and coupling analysis method.These conclusions provide a reference for the seismic design of equipment-structure coupling system.