Study On The Shafting Alignment For Ship Based On Slipway Aligning

Shafting alignment is a very important and time-consuming process during the designand construction of ship, The quality of shafting alignment is related to the normal operationof ship and security of crew directly. For the reason of being calculated or measured difficultof hull deformation and lack of experience in shafting aligned on slipway both theoreticallyand practically, currently, the most popular procedure of alignment work is to complete theinitial alignment of main engine and shafting on slipway first, and then, final alignment isfinished after the launch of ship, following, all auxiliary equipments associated with mainengine are installed. Completing the transformation of installation mode from launch toslipway with the consideration of actual factors can shorten the time of ship building greatly,and meantime it can provide a long-term, stable and normal condition for the operation ofship and shafting.In this thesis, a generalized summarization regarding modeling, alignment calculationand optimization was made for ship shafting. Some factors regarding hull deflection was alsodiscussed. Furthermore, the calculation and method of measurement about hull deformationhave been analyzed. On this basis, Finite Element Analysis(FEA) method with high accuracywas chosen to build the entire analysis model in consideration of bearing stiffness andshearing deformation of beam, Gaussian Elimination was used to solve the equation. And also,Improved Genetic Algorithm(IGA) was developed to solve the optimization calculation ofshafting. Taking the propulsion system of some bulk carrier as an example, influence of hulldeformation on shafting alignment was analyzed, shafting alignment calculation based onslipway aligning were carried out. The presented analysis method was proved to be high-efficient and the derived bearing offset could be used in ship shafting, which establishedtheoretical basis for the shafting aligned on slipway.In order to improve the result of alignment, shock response and swing vibration werealso studied from the perspective of design, which could provide reference for the rationalarrangement of bearings. Furthermore, gyroscopic effect were calculated and analyzed.