http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Analytical procedures for torsional vibration analysis of ship power transmission system
Senjanović,, Ivo,Hadx17e,ix107,, Neven,Murawski, Lech,Vladimir, Nikola,Alujevix107,, Neven,Cho, Dae-Seung Elsevier 2019 ENGINEERING STRUCTURES Vol.178 No.-
<P><B>Abstract</B></P> <P>In this paper two relatively simple analytical procedures for free and forced torsional vibration analysis of ship power transmission systems are developed. In the first, approximate procedure, the shaft line is modelled as a two-mass system and analytical solution of the differential equations of motion is given. In the second one, a multi degree of freedom (d.o.f.) problem of the complete propulsion system is solved by the Rayleigh-Ritz method. A special attention is paid to the determination of the contribution of each cylinder to the primary and secondary engine torques by taking into account the firing order. The application of the two procedures is illustrated in the case of a typical propulsion system of a merchant ship with a slow-speed main engine connected directly to the propeller by a relatively short shaft line. The obtained results are verified by a comparison with measurements. All classification societies require calculation of the propulsion system operating parameters, but they do not provide simplified formulae for vibration analysis. The outlined analytical procedures can be used for the estimation of torsional vibration of the shaft line in the preliminary ship design stage as well as for ships in service.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Condensed two-mass model of shaft line. Analytical solution of diff. eqs. of motion. </LI> <LI> Simplified multi-mass model of shaft line. Rayleigh-Ritz method. Analytical solution. </LI> <LI> Formulation of cylinder torque and engine primary and secondary torque. </LI> <LI> Physically based transfer factor of engine excitation to shaft response. </LI> <LI> Comparison with FEM. Verification by measurement. High accuracy. </LI> </UL> </P>
Analytical Solution for Free Vibrations of a Moderately Thick Rectangular Plate
Senjanović,, Ivo,Tomix107,, Marko,Vladimir, Nikola,Cho, Dae Seung Hindawi Limited 2013 Mathematical problems in engineering Vol.2013 No.-
<P>In the present thick plate vibration theory, governing equations of force-displacement relations and equilibrium of forces are reduced to the system of three partial differential equations of motion with total deflection, which consists of bending and shear contribution, and angles of rotation as the basic unknown functions. The system is starting one for the application of any analytical or numerical method. Most of the analytical methods deal with those three equations, some of them with two (total and bending deflection), and recently a solution based on one equation related to total deflection has been proposed. In this paper, a system of three equations is reduced to one equation with bending deflection acting as a potential function. Method of separation of variables is applied and analytical solution of differential equation is obtained in closed form. Any combination of boundary conditions can be considered. However, the exact solution of boundary value problem is achieved for a plate with two opposite simply supported edges, while for mixed boundary conditions, an approximate solution is derived. Numerical results of illustrative examples are compared with those known in the literature, and very good agreement is achieved.</P>