scholarly journals ANÁLISE DINÂMICA NÃO LINEAR GEOMÉTRICA DE TRELIÇAS PLANAS

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.

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Tao He ◽  
Xiqun Lu ◽  
Jingzhi Zhu

The analytical mobility method for dynamically loaded journal bearings was presented, with the intent to include it in a general computational program, such as the dynamic analysis program, that has been developed for the dynamic analysis of general mechanical systems. An illustrative example and numerical results were presented, with the efficiency of the method being discussed in the process of their presentation.


2013 ◽  
Vol 66 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Jorge Luis Palomino Tamayo ◽  
Armando Miguel Awruch ◽  
Inácio Benvegnu Morsch

A numerical model using the Finite Element Method (FEM) for the nonlinear static and dynamic analysis of reinforced concrete (RC) beams, plates and shells is presented in this work. For this purpose, computer programs based on plasticity theory and with crack monitoring capabilities are developed. The static analysis of RC shells up to failure load is carried out using 9-node degenerated shell finite elements while 20-node brick finite elements are used for dynamic applications. The elasto-plastic constitutive law for concrete is coupled with a strain-rate sensitive model in order to take into account high loading rate effect when transient loading is intended. The implicit Newmark scheme with predictor and corrector phases is used for time integration of the nonlinear system of equations. In both cases, the steel reinforcement is considered to be smeared and represented by membrane finite elements. Various benchmark examples are solved with the present numerical model and comparisons with other published data are performed. For all examples, the path failure, collapse loads and failure mechanism is reproduced with great accuracy.


2018 ◽  
Vol 35 (3) ◽  
pp. 305-313 ◽  
Author(s):  
C. Rebiai

ABSTRACTIn this investigation, a new simple triangular strain based membrane element with drilling rotation for 2-D structures analysis is proposed. This new numerical model can be used for linear and dynamic analysis. The triangular element is named SBTE and it has three nodes with three degrees of freedom at each node. The displacements field of this element is based on the assumed functions for the various strains satisfying the compatibility equations. This developed element passed both patch and benchmark tests in the case of bending and shear problems. For the dynamic analysis, lumped mass with implicit/explicit time integration are employed. The obtained numerical results using the developed element converge toward the analytical and numerical solutions in both analyses.


Author(s):  
Seunghoon Shin ◽  
Guangyoung Sun ◽  
Juwon Lee ◽  
Kangboo Kim

In this paper, the structural dynamics study of the frame to support 15MW compressor is suggested. This study used the steel-concrete hybrid frame to support a large compressor system. This paper provided experimental and analytical method to structural design the hybrid frame by considering in rotordynamics and aerodynamics. Dynamic characteristics of the frame have to be identified to tune the finite element model’s boundary condition and to avoid resonance. Therefore modal testing of the frame is performed and boundary conditions are modified applying to the previously obtained modal parameters. While compressor is operated, multiple dynamic loads of compressor, motor and expander may excite on the frame. The total dynamic load is derived by axial aerodynamic load of impeller, radial load of gear and unbalance load of rotor. After dynamic analysis completion, the analysis result is compared with test result to verify the accuracy of analysis. Through this structural dynamic analysis, structural vibration response of hybrid frame can be estimated.


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