Study On Vibration And Damping Reduction Of Hull Plated Grillage

With the globalization of economy,the development of international trade and the exploration of marine resources,the ship is more and more important.When the ship is sailing on the sea,it will be inspired by the wave,the propeller and the main engine.The polymer viscoelastic material arises at the historic moment.Because of its high damping capacity,it can consume a large amount of energy in the vibration of the structure.In this paper,the damping vibration test and simulation research of the plated grillage are studied:Through theoretical calculation of the loss factor of beam structure covered with damping material,find out the relationship between the composite structure loss factor and damping layer thickness,damping material loss factor and modulus,so as to provide a reference value for the plated grillage structure with damping layer thickness.Then,the modal and random response analysis of the plated grillage structure with damping material are carried out.The change of modal frequency,the prediction of damping vibration effect and the relationship between the vibration reduction effect and the position of the exciting point are studied.By means of modal test and random vibration test,the natural frequency,natural vibration mode and modal damping ratio of the structure before and after the installation of damping material are measured.The test and simulation results and errors analysis are analyzed by comparison with the inner bottom plated grillage,the bulkhead plated grillage and the double bottom plated grillage before and after the damping.At the same time,the rationality of the simulation method is verified.Finally,according to the simulation analysis of the double bottom plated grillage,the damping effect with different thickness is compared,and the proper damping layer thickness for the double bottom structure is obtained.