Research On Low Frequency Vibration Control Of Platform Structure Based On Inertia Absorber

Steel platform deck structures are widely used in a variety of production structures,such as oil and gas production platforms,because of their high load carrying capacity,low cost and easy installation and disassembly.Oil and gas production platform is an infrastructure integrating the functions of exploitation,processing,storage and operation environment monitoring,as well as the base for staff to work and live.Therefore,it is significant to study how to improve the production safety and stability of the platform.In the current research on vibration control of platform structures,researchers mainly pay attention to the damages caused by natural loads such as earthquake and ice-induced.And in most cases,the influence of external loads on the vibration is reduced by improving the platform structure,increasing stiffness or setting various vibration damping devices.However,the problems of structural fatigue damage and the reduction of the comfort of the staff caused by low-frequency vibration of mechanical equipment on the platform are still not fully studied.Moreover,In addition,traditional vibration damping devices often have problems such as excessive added mass and deformation in low-frequency vibration control occasions,which has an adverse impact on its application scope and performance.In this paper,considering the problems of low-frequency vibration control additional mass and large size space existing in the traditional dynamic vibration absorber,the low-frequency vibration generated by mechanical equipment on the platform deck is studied to reduce by using the inertia capacity damping device with mass amplification characteristics.The design method and process of the inerter based dynamic vibration absorber applied to low-frequency vibration reduction of the platform structure are established,and the vibration suppression characteristics of the inerter based dynamic vibration absorber are analyzed and the rationality of the design procedures is verified by means of theoretical calculation,simulation and experiment.The main work of this paper are as follows:1.Aiming at the vibration reduction of platform structure,the application design method of inerter based dynamic vibration absorber is studied in detail.The technical process from position selection to specific parameter design is established,the parameter design formula is derived,the vibration characteristics are analyzed,and the general design rules of the absorber in the vibration reduction of platform structure are summarized.2.The simulation model of the platform deck structure is established.The vibration characteristics of the platform model are studied based on the proposed design method and process of the inerter based dynamic vibration absorber.According to the results of modal and frequency response analysis,a reasonable vibration reduction scheme is formulated,and the equivalent parameters of each vibration reduction point are solved and compared.3.According to the formulated vibration reduction scheme and the parameter design method,the inerter based dynamic vibration absorber is designed to reduce the vibration of the platform model by referring to the equivalent parameters of each vibration reduction point.The vibration reduction effect of the inerter based dynamic vibration absorber is comprehensively investigated.The validity of the absorber and the rationality of the design method are verified by comparing the theoretical and the simulation results.And completed the experimental verification of relevant contents.In this paper,the design method and process of the inertial vibration absorber in the vibration protection of the platform structure are studied,which provides a feasible technical idea and method for effectively solving the low-frequency vibration problems of similar structures such as oil and gas production platforms and improving the low-frequency vibration suppression performance of traditional damping devices,Therefore,it has important practical engineering application significance.