Rub-impact dynamic analysis of a rotor with multiple wide-chord blades under the gyroscopic effect and geometric nonlinearity

2022 ◽  
Vol 168 ◽  
pp. 108563
Author(s):  
Haijiang Kou ◽  
Yuxiang Shi ◽  
Jiaojiao Du ◽  
Zhida Zhu ◽  
Fan Zhang ◽  
...  
2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Leandro Damas Oliveira ◽  
Wellington Andrade Da Silva ◽  
William Taylor Matias Silva ◽  
Rodrigo Gustavo Delalibera

RESUMO: Este trabalho trata da análise dinâmica de treliças no plano, onde estudam-se os efeitos da não-linearidade geométrica nessas estruturas quando solicitadas por carregamentos dinâmicos. Nesse contexto, define-se a formulação baseada na análise não-linear geométrica que descreve o comportamento de treliças discretizadas por elementos finitos, utilizando-se o método corrotacional. Para a resolução dos sistemas não-lineares, utiliza-se o método numérico de Newton-Raphson e para a integração temporal dessas equações, utiliza-se o método de Newmark. Por meio dos eixos corrotacionais é possível separar os movimentos de corpo rígido dos movimentos deformacionais. Para verificar a eficácia da formulação estudada no presente trabalho, foram realizados exemplos com treliças planas usualmente empregadas em análises com grandes não-linearidades geométricas na literatura técnica. De forma geral, a formulação estudada apresentada se demostrou eficiente para a análise dinâmica de treliças com grandes não-linearidades geométricas.
 
 ABSTRACT: This paper deals with dynamic analysis of two dimensional trusses, where the effects of geometric nonlinearity in these structures is studied when subjected by dynamic loads. In this context, the formulation based on geometric nonlinear analysis that describes the behavior of trusses discretized by finite elements using the Corotational Method is developed. For solving nonlinear systems is used the Numerical Method of Newton-Raphson and for the time integration of these equations is used Newmark Method. Through the corotational axis is possible to separate the rigid body movements from deformational movements. To verify the accuracy of the formulation studied in the present work, examples with plane trusses usually employed in analyzes with large geometric non-linearities in the technical literature were made. In general, the studied formulation presented was efficient for the dynamic analysis of trusses with large geometric nonlinearities.


2019 ◽  
Vol 12 (2) ◽  
pp. 308-328
Author(s):  
H. CARVALHO ◽  
G. QUEIROZ ◽  
P. M. L. VILELA ◽  
R. H. FAKURY

Abstract Usually, the analysis of structures under wind loading is performed using an equivalent static analysis, where the influence of floating response is taken into account by the gust factor. This methodology can be used in case of rigid structures for not presenting a considerable dynamic response. More flexible structures, in particular those lightly damped, may show an important resonant response and their dynamic properties must be considered in the analysis. The aim of this paper is to present a methodology for dynamic analysis of structures under wind loading considering the geometric nonlinearity, the vibration caused by the kinetic energy of wind gusts and the aerodynamic damping due to the relative movement between this structure and the wind. The formulation proposed is applied to a 180-meter-high concrete chimney and the results were compared with those obtained through the recommendation given in the standard ABNT NBR 6123:1988 [2] for the dynamic structural analysis.


2012 ◽  
Vol 591-593 ◽  
pp. 2143-2147
Author(s):  
Chuan Dong Lv ◽  
Ji Fei Cai ◽  
Guang Li ◽  
Rui Ming Fang

Brushes-type blanket washer’s function is rubbing a high speed spinning brush roller against blanket roller, so as to clean the paper-lints and ink which adhere to the surface of blanket cylinder. It is very important to do a research into the dynamic structural analysis of the washer which determines the stability of this equipment. With the gyroscopic effect dynamic analysis of brush blanket, we get the relation curve between central offset of the washer and the load of permanent joint. The result show that a minute alteration of the central offset causes effect change of the load. This result provides a theoretical basis to control the effect change and then improve the stability and decrease the cost.


Author(s):  
Naoki Sugano ◽  
Koichi Honke ◽  
Etsujiro Imanishi ◽  
Kazuo Hashimoto

Abstract In this paper, the dynamic analysis of link structures including both flexible and rigid bodies is developed. The model for flexible bodies is based on FEM theory, and geometric nonlinearity effect is taken into account. Moreover, in the flexible rigid link structure, dependent variables are eliminated using topological information. The equation of the total system obtained in this study is in the form of ODE and can be solved efficiently.


2020 ◽  
Vol 19 (3) ◽  
pp. 321-334
Author(s):  
Élcio Cassimiro Alves ◽  
◽  
Larissa Bastos Martinelli ◽  

The objective of this paper is to present the formulation for optimizing truss structures with geometric nonlinearity under dynamic loads, provide pertinent case studies and investigate the influence of damping on the final result. The type of optimization studied herein aims to determine the cross-sectional areas that will minimize the weight of a given structural system, by imposing constraints on nodal displacements and axial stresses. The analyses are carried out using Sequential Quadratic Programming (SQP), available in MATLAB’s Optimization Toolbox™. The nonlinear finite space truss element is defined with an updated Lagrangian formulation, and the geometrically nonlinear dynamic analysis performed herein combines the Newmark method with Newton-Raphson iterations. The dynamic analysis approach was validated by comparing the results obtained with solutions available in the literature as well as with numerical models developed with ANSYS® 18.2. A number of optimization examples of planar and space trusses under dynamic loading with geometric nonlinearity are presented. Results indicate that the consideration of damping effects may lead to a significant reduction in structural weight and that such weight reduction is proportional to increases in damping ratio.


2011 ◽  
Vol 131 (2) ◽  
pp. 166-170 ◽  
Author(s):  
Yoshihiro Nakata ◽  
Hiroshi Ishiguro ◽  
Katsuhiro Hirata

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