Computer Modeling Techniques for Array Antennas on Complex Structures

1997 ◽  
Author(s):  
D. C. Jenn
1997 ◽  
Author(s):  
In-Byeong Kang ◽  
Noel D. Samaan ◽  
Malcolm R. Haskard ◽  
Namsoo Kim

2000 ◽  
Vol 123 (1) ◽  
pp. 89-99 ◽  
Author(s):  
R. Bladh ◽  
M. P. Castanier ◽  
C. Pierre

Component mode synthesis (CMS) techniques are widely used for dynamic analyses of complex structures. Significant computational savings can be achieved by using CMS, since a modal analysis is performed on each component structure (substructure). Mistuned bladed disks are a class of structures for which CMS is well suited. In the context of blade mistuning, it is convenient to view the blades as individual components, while the entire disk may be treated as a single component. Individual blade mistuning may then be incorporated into the CMS model in a straightforward manner. In this paper, the Craig–Bampton (CB) method of CMS is formulated specifically for mistuned bladed disks, using a cyclic disk description. Then a novel secondary modal analysis reduction technique (SMART) is presented: a secondary modal analysis is performed on a CB model, yielding significant further reduction in model size. In addition, a straightforward non-CMS method is developed in which the blade mistuning is projected onto the tuned system modes. Though similar approaches have been reported previously, here it is generalized to a form that is more useful in practical applications. The theoretical models are discussed and compared from both computational and practical perspectives. It is concluded that using SMART, based on a CB model, has tremendous potential for highly efficient, accurate modeling of the vibration of mistuned bladed disks.


1986 ◽  
Vol 13 (2) ◽  
pp. 150-161 ◽  
Author(s):  
M. Frenette ◽  
P. Y. Julien

Computer modeling techniques are used for predicting soil losses from overland flow and subsequent suspended sediment yield from large watersheds. The model LAVSED-I (LAVal SEDidentological model No. 1) is based on the universal soil-loss equation of Wischmeier and Smith and the equation of Kiline and Richardson. The model subdivides the watershed into square units varying in size from 0.3 to 3000 km2 and the computational procedure is subdivided in four components: precipitation, physical characteristics of watersheds, erosion/sedimentation, and land use. This paper describes the operational development and the application of the model to a prototype-scale watershed. A map for the annual soil loss is presented for the Chaudière watershed (area = 5830 km2). Results of mapping compared with the sediment yield observed are shown in the paper.


2013 ◽  
Vol 85 ◽  
pp. 125-134 ◽  
Author(s):  
Kenji Takizawa ◽  
Bradley Henicke ◽  
Anthony Puntel ◽  
Nikolay Kostov ◽  
Tayfun E. Tezduyar

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