Research On Equivalent Modeling Of Typical Parts Of Turbine And Dynamic Response Characteristics Of Coupled High Temperature And High Working Stress

During the service of the ships and their shipborne equipment,they will not only face the complicated and changeable Marine environment,but also be suddenly impacted by bombs,torpedoes and other underwater weapons,which will pose a certain threat to the ship structure and its shipborne equipment.In this paper,the commonly used finite element simulation method is generally used to carry out the impact environment of underwater explosion structures,and the anti-explosion and anti-impact performance of ships and shipborne equipment is evaluated and analyzed,so as to better meet the requirements of service functions.In this paper,the impact resistance performance of the ship’s power plant,namely the Marine steam turbine,is studied,and the impact response characteristics of the steam turbine and its typical components are analyzed,so that to provide some guidance for the subsequent optimal design of the turbine structure and its impact resistance performance.First of all,with the impact response of the structure under underwater explosion as the research background,the process of underwater explosion and the characteristics of explosion products,including shock wave and bubble load,as well as their propagation law are studied,and the impact environment and impact spectrum generated by underwater explosion in the frequency domain,the sinusoidal change course in the time domain and the triangle change course are studied and analyzed.Secondly,the equivalent modeling method is used to establish the finite element model of typical turbine components,including the model of the overall structure of the turbine,the high and low pressure rotor,the baffle,the front and rear bearing seats and their connecting bolts.The model of the whole structure of the turbine is analyzed in the free mode,and the validity of the finite element model of the turbine is verified.Afterwards,the method of time domain analysis is adopted to check the initial acceleration conditions of the overall structure of the turbine,and the acceleration impact loads are respectively applied to the turbine in the vertical,horizontal,longitudinal directions,and the analysis of the curve law of the acceleration time-history curve clearly identified the dangerous areas and weak links of the turbine.According to the German standard BV0430-85 for the impact load,this paper designs a series of acceleration impact load conditions,and the acceleration time history curves of cylinder,rotor and baffle under the action of vertical and lateral acceleration impact loads are analyzed.Based on the precious work,the maximum acceleration and pulse width were changed and dimensionless,respectively.The variation law of the non-dimensional Mises stress of the cylinder,the rotor,and the diaphragm with the change curve of the maximum acceleration and pulse width is studied respectively.By changing the pulse width of acceleration,the limit value of acceleration impact load in vertical,transverse and longitudinal of the whole structure of the turbine is obtained,and the dangerous area and weak links of the turbine are calculated.Finally,the finite element model of the blade was established by using an equivalent modeling method to analyze the structure and failure form of the turbine rotor blade,as well as the key factors affecting the analysis of the blade impact response.key influencing factors of the blade impact response of the turbine rotor blade,and aim at the key factor of the material parameters that affect the blade impact response,the impact response analysis of the turbine blade structure is carried out.Selecting different blade material parameters respectively to obtain the deformation stress,and strain cloud diagrams of the blade at different temperatures.Through the analysis of the deformation,stress,and strain results of the blade,the impact response characteristics of the blade under high temperature and pressure conditions are obtained.And apply acceleration impact load to the blade in the vertical,horizontal and longitudinal directions,and analyze by drawing the shock spectrum which provides a reference for the subsequent optimization design of the impact resistance of the blade.