Torsional Vibration Calculation Of Complex Branched Shafting For Combined Dual Engines System

With the development of modern Ship Industry and Internal Combustion Engine Industry, more and more complex branched systems are used on board. The typical complex branched system on ship is combined dual engines system with Power Take Off system. So it is important for us to choose accurate calculation methods and models, and make friendly program to finish the torsional vibration calculation of this complex system.There are many methods, which can solve torsional vibration of complex branched system. These methods have their own advantages and disadvantages. Based on the traditional dynamic matrix method, which is fit for system without branches, we modified this method to enable it solve torsional vibration of branched system. These modified methods have been used in many conditions successfully. We used Jaccobi method to finish the free vibration calculation. Before calculating forced vibration, simple harmonic coefficient analysis is discussed in this paper. By using the condition of orthogonality of normalization vibration mode, the inertia matrix, the stiffness matrix and the damping matrix are become diagonal matrix. Based on Windows and Visual C++, a TV code, which is fit for torsional vibration calculation, is compiled. With the necessary data inputted by user, the code can output the data and pictures of calculation. The cod has been used to calculate torsional vibration of many real shafting. Finally, it also has been used to calculate complex branched system with combined dual engines system. The calculated results are satisfactory and in concordance with the measured results.