The Research On Acoustics Design Of Complicated Equipment Base

Machine base as an important channel to transfer vibration to the hull, its mechanical properties directly affect the noise level of the whole unit. In this paper, in order to meet the design and control requirements of structure noise of a certain type of steam turbine generator set, we proposed a design scheme of a new type of combined assembly base, under the premise of the overall design.Firstly, verified the advantages and characteristics of the composite structure concept model on damping effect based on finite element analysis. Simultaneously, analyzed and studied the effects of different structural parameters on vibration transfer characteristics, and it provided guidance for the base design.Secondly, designed structure of the base, using V type assembled structure, upper and under frame are assembled into a whole unit through elastic rubber damping elements. A variety of internal support structure which is conducive to sound insulation effect is applied, and base structure was analyzed and optimized by finite element method, ensure that the base stiffness and strength meet the design requirements.Then, calculated inherent frequency and vibration mode of upper frame, under frame, assembled base and the whole machine under free boundary conditions, and avoid resonance between the base mode and disturbance frequency. And the modal test is carried out, and the natural frequency and mode shape are in good agreement with the finite element calculation results, which verified the accuracy of the finite element model.Finally, in order to obtain the vibration transfer characteristics of the composite structure base, calculated the frequency response of the whole machine using finite element method, and predicted the effect of composite structure base on vibration transfer control from the perspective of design. The frequency response characteristics test of the prototype is also presented. The results show that the finite element calculation results are in agreement with the experimental results. Not only verified the validity of the modeling and analysis techniques, as well as to verify the feasibility of composite structure base design.