Model identification and dynamic analysis of ship propulsion shaft lines


1 Department of Mechanical Engineering, Arak University of Technology, University St., Arak, Iran

2 Center of Excellence in Experimental Solid Mechanics and Dynamics, Iran University of Science and Technology, Narmak, Tehran, Iran


Dynamic response analysis of mechanical structures is usually performed by adopting numerical/analytical models. Finite element (FE) modeling as a numerical approach plays an important role in dynamic response analysis of complex structures. The calculated dynamic responses from FE analysis are only reliable if accurate FE models are used. There are many elements in real mechanical structures which make constructing accurate FE models difficult. For example, modeling the boundary supports of mechanical structures are usually challenging because of the uncertainties existing in their stiffness values. The stiffness values of boundary supports can be identified by using experimental natural frequencies and hence the FE model can be corrected. In this paper, the FE modeling and updating of propulsion shaft lines in a ship structure is considered by employing experimental modal parameters, i.e. natural frequencies. Natural frequencies of shaft lines are measured by performing experimental vibration testing. The corrected FE models are used and dynamic response analysis of shaft lines is conducted


  • Finite element modeling of shaft lines for a ship structure is considered.
  • The stiffness of the boundary supports are modelled (F.E.) using spring elements.
  • Natural frequencies of the shaft lines are measured through modal testing.
  • F.E. models are updated through eigensensitivity analysis of natural frequencies.
  • Dynamic analysis is performed on updated models and Campbell diagram is obtained.


Main Subjects

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