Review article
Advanced Methods for Static and Dynamic Shafting Calculations
W. Schiffer
Abstract
This article introduces a computer program developed by Wärtsilä Switzerland which provides a three-dimensional model of the shafting for the calculation of coupled vibrations, alignment and whirling in a ship propulsion plant. Based on the fi nite-element method the program covers both dynamic and static problems. Each node has six degrees of freedom. The following features are included: calculation in frequency range and time domain, linear and nonlinear bearing characteristic, consideration of variation of running gear inertia, and optimization of engine parameters. The mathematical model of the shaft line with all associated parameters and boundary conditions are
represented by calculation results and validated by measurement. An everyday example for the calculation of coupled axial vibrations with the associated measured data is shown in this paper.
Furthermore the infl uence of the variation of torsional inertia is demonstrated and a possibility for reduction of torsional stress in the crankshaft by injection timing optimization is explained. As an
example for the static capabilities the reverse bearing offset calculation based on measured web defl ections, bearing loads and bending moments is demonstrated.
Keywords
bearings; coupled vibrations; shafting; ship propulsion plants; torsional stress
Hrčak ID:
13545
URI
Publication date:
29.6.2007.
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