Nonlinear Damping Mechanics and Finite Element Model for the Static and Damped Free-Vibration Analysis of Composite Strips

2013 ◽  
pp. 69-101
Author(s):  
Dimitrios I. Chortis
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Finite Element Model ◽  
Vibration Analysis ◽  
Free Vibration Analysis ◽  
Element Model ◽  
Nonlinear Damping

An Efficient Three Nodded Finite Element Formulation for Free Vibration Analysis of Sandwich Arches with Graded Metallic Cellular Core

2020 ◽  
Vol 12 (06) ◽  
pp. 2050069
Author(s):  
Mohammad Amir ◽  
Mohammad Talha
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Finite Element Model ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Core Layer ◽  
Element Model ◽  
Element Formulation ◽  
Present Formulation ◽  
Porosity Coefficient

An efficient finite element model based on three nodded element has been developed for the vibration analysis of sandwich arches with graded metallic cellular (GMC) core. The present formulation is based on the higher-order shear deformation theory and orthogonal curvilinear coordinate axes. The arch consists of two isotropic face sheets and a GMC core layer. The internal pores in the core layer follow the different types of distributions. The material properties of the GMC core layer of the sandwich arches vary in the thickness direction as a function in terms of porosity coefficient and mass density. Three types of porosity distributions have been considered to accomplish the vibration responses of sandwich arches. The present formulation is validated with limited results available in the literature. Few new results are computed and the effects of different influencing parameters such as porosity coefficient [Formula: see text], porosity distribution type, the thickness-to-length ratio [Formula: see text], boundary conditions and opening angle [Formula: see text] on the free vibration characteristics of sandwich arches with the GMC core are observed. The present finite element model gives better convergence and more accurate results than a conventional two nodded element-based finite element model.

US-FE-LSPIM TRI3 Element for Free Vibration Analysis

2012 ◽  
Vol 246-247 ◽  
pp. 1278-1282 ◽  
Author(s):  
Hui Hui Chen ◽  
Cheng Jia
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Vibration Analysis ◽  
Free Vibration Analysis ◽  
Element Model ◽  
Benchmark Problems ◽  
Element Formulation ◽  
Shape Functions ◽  
The Individual ◽  
Element Shape

For the purpose of construction an effective element model, the US- FE-LSPIM TRI3 element formulation, which is based on the concept of unsymmetric finite element formulation, is established. Classical linear triangle shape functions and FE-LSPIM TRI3 element shape functions are used as test and trial functions respectively. Classical linear triangle shape functions fulfill the requirements of continuity in displacement field for test functions. The FE-LSPIM TRI3 element shape functions synthesize the individual strengths of meshfree and finite element methods so they are more proper for trial functions. The element is applied in free vibration analysis of two dimension solids. Typical benchmark problems are solved. The results show that this element is more accurate and capable of good performances under both regular and irregular meshes.

scholarly journals Free vibration analysis of coupled sloshing-flexible membrane system in a liquid container

2018 ◽  
Vol 25 (1) ◽  
pp. 84-97 ◽  
Author(s):  
Amir Kolaei ◽  
Subhash Rakheja
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Free Vibration ◽  
Finite Element Model ◽  
Liquid Membrane ◽  
Free Vibration Analysis ◽  
Element Model ◽  
Computational Time ◽  
Flexible Membrane ◽  
Liquid Free Surface

A finite element model is developed to study free vibration of a liquid in a tank of arbitrary geometry with a flexible membrane constraining the liquid free-surface. A variational formulation is initially developed using the Galerkin method, assuming inviscid, incompressible and irrotational flow. The resulting generalized eigenvalue problem is then reduced by considering only the elements on the liquid free-surface, which significantly reduces the computational time. The proposed physical model is subsequently implemented into the FEniCS framework to obtain coupled hydroelastic liquid-membrane frequencies and modes. The coupled frequencies are compared with those reported for rectangular and upright cylindrical tanks using analytical methods in order to illustrate the validity of the finite element model. The results are subsequently presented for a horizontal cylindrical tank with an elastic free-surface membrane for different fill ratios and tank lengths. The effects of the membrane tension on the free vibration of the liquid in the tank are further investigated by comparing the coupled liquid-membrane frequencies with slosh frequencies of the liquid alone. It is shown that sloshing frequencies can be effectively shifted to higher values to prevent resonance in partially filled moving containers.

scholarly journals Free Vibration Analysis of Cable Stayed-Bridge by Finite Element Method

2019 ◽  
Vol 12 (4) ◽  
pp. 67-72
Author(s):  
Haneen A. Mahmood ◽  
Zaid S. Hammoudi ◽  
Ali Laftah Abbas
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Free Vibration Analysis ◽  
Element Model ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Cable Stayed Bridge

A delicate analysis of the natural frequencies and mode shapes of a cable stayed bridge is essential to the solution of its dynamic responses due to seismic, wind and traffic loads. In this paper, a bridge with geometry comparable to the Quincy Bayview Bridge was modelled in order to explore the significance of the three dimensional and free vibration analysis. This paper provides a detail of the bridge and the equivalent cross section of the three-dimensional finite element model implicating cables, the bridge deck and pylons as well as the boundary conditions and free vibration analysis by Ansys15.0. The bridge was analyzed to free vibration to obtaine the natural frequency and mode shape. result of this paper present the natural frequencies and mode shapes of the bridge. The method of modelling cables is also studied. It is found that modelling cables as multi beam elements provides better results than using the traditional (and simpler) method of modeling them as single tensile elements.

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