@Article{cmes.2020.08789,
AUTHOR = {Siyang Piao, Huajiang Ouyang, Yahui Zhang},
TITLE = {Beam Approximation for Dynamic Analysis of Launch Vehicles Modelled as Stiffened Cylindrical Shells},
JOURNAL = {Computer Modeling in Engineering \& Sciences},
VOLUME = {122},
YEAR = {2020},
NUMBER = {2},
PAGES = {571--591},
URL = {http://www.techscience.com/CMES/v122n2/38314},
ISSN = {1526-1506},
ABSTRACT = {A beam approximation method for dynamic analysis of launch vehicles 
modelled as stiffened cylindrical shells is proposed. Firstly, an initial beam model of the 
stiffened cylindrical shell is established based on the cross-sectional area equivalence 
principle that represents the shell skin and its longitudinal ribs as a beam with annular 
cross-section, and the circumferential ribs as lumped masses at the nodes of the beam 
elements. Then, a fine finite element model (FE model) of the stiffened cylindrical shell 
is constructed and a modal analysis is carried out. Finally, the initial beam model is 
improved through model updating against the natural frequencies and mode shapes of the 
fine FE model of the shell. To facilitate the comparison between the mode shapes of the 
fine FE model of the stiffened shell and the equivalent beam model, a weighted nodal 
displacement coupling relationship is introduced. To prevent the design parameters used 
in model updating from converging to incorrect values, a pre-model updating procedure 
is added before the proper model updating. The results of two examples demonstrate that 
the beam approximation method presented in this paper can build equivalent beam 
models of stiffened cylindrical shells which can reflect the global longitudinal, lateral and 
torsional vibration characteristics very well in terms of the natural frequencies.},
DOI = {10.32604/cmes.2020.08789}
}