DYNAMIC BEHAVIOR OF AXIALLY MOVING SYSTEMS WITH ELASTIC SUPPORTS

Author(s):  
Gabriella Nehemy ◽  
Paulo Gonçalves ◽  
EDSON CAPELLO SOUSA
Author(s):  
Giuseppe Pennisi ◽  
Olivier Bauchau

Abstract Dynamics of axially moving continua, such as beams, cables and strings, can be modeled by use of an Arbitrary La-grangian Eulerian (ALE) approach. Within a Finite Element framework, an ALE element is indeed a non-material system, i.e. a mass flow occurs at its boundaries. This article presents the dynamic description of such systems and highlights the peculiarities that arise when applying standard mechanical principles to non-material systems. Starting from D’Alembert’s principle, Hamilton’s principle and Lagrange’s equations for a non-material system are derived and the significance of the additional transport terms discussed. Subsequently, the numerical example of a length-changing beam is illustrated. Energetic considerations show the complex dynamic behavior non-material systems might exhibit.


2015 ◽  
Vol 28 (6) ◽  
pp. 706-721 ◽  
Author(s):  
Yanqing Wang ◽  
Wei Du ◽  
Xiaobo Huang ◽  
Senwen Xue

2014 ◽  
Vol 10 (1) ◽  
pp. 10-15
Author(s):  
Oľga Ivánková ◽  
Dušan Drobný ◽  
Soňa Medvecká

Abstract The paper describes effects of bracing of high-rise buildings upon their static and dynamic behaviour. In static and dynamic analyses, values of displacement for 4 different variants of stiffening elements distribution were calculated. The calculations were made for building both fixed into the ground and rested on elastic supports. The building was modelled as a 3D variant using Finite Element Method (FEM) in program Scia Engineer.


2002 ◽  
Vol 55 (4) ◽  
pp. 325-350 ◽  
Author(s):  
Mohamad S Qatu

Laminated composite shells are increasingly being used in various engineering applications including aerospace, mechanical, marine, and automotive engineering. With the increasing awareness of and sensitivity to structural noise and vibration, research covering the dynamic behavior of composite shells has received considerable attention. The purpose of this article is to review most of the recent research done in this field. Review of the literature on the dynamic behavior of homogeneous shells is covered in Part 2 of this article to be published in the September 2002 issue of AMR. Research on shell dynamics is found to be mainly free vibration analyses. The review is conducted with emphasis given to the theory being applied (thin, thick, 3D, nonlinear, …), the analysis method (exact, Ritz, finite elements, …), complicating effects (initial stress, imperfection, added masses and springs, elastic supports, rotating shells, and others), and the various shell geometries that were subject to vibration research (cylindrical, conical, spherical, and others). There are 374 references cited in this review article.


2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.


2006 ◽  
Vol 12 (4) ◽  
pp. 33-37
Author(s):  
V.E. Shatikhin ◽  
◽  
L.P. Semenov ◽  
V.S. Khoroshylov ◽  
V.M. Popel' ◽  
...  
Keyword(s):  

Author(s):  
Yuichi Niibori ◽  
Yasunori Kasuga ◽  
Hiroshi Kokubun ◽  
Kazuki Iijima ◽  
Hitoshi Mimura

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