scholarly journals A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams

2021 ◽  
Author(s):  
Jean-Jacques R. Boiluea Bekuit
Keyword(s):  
Finite Element ◽  
Piezoelectric Layer ◽  
Layer Structure ◽  
Time Integration ◽  
Beam Theory ◽  
Viscoelastic Layer ◽  
Element Formulation ◽  
Transverse Displacement ◽  
Passive Damping ◽  
Dimensional Finite Element

Active-passive damping is getting more popular with designers because it combines the complementary passive and active features in the control of structural vibrations. The classical three-layer structure has a viscoelastic-layer sandwiched between the host beam and a piezoelectric-layer. The more prevalent assumptions for modeling the system are the use of Euler-Bernoulli beam theory for both the host beam and piezoelectric-layer, and Timoshenko beam theory for the viscoelastic-layer. The assumption that transverse displacement is constant through the thickness limits accuracy and applicability of the model. The current formulation expresses the through-the-thickness dependency of the field variables as polynomials while their span dependency across a finite element is cubically interpolated. The versatility of the formulation is demonstrated via static and dynamic studies of examples taken from the literature. A beam treated with active-passive damping is presented and examined. The constitutive relation of the viscoelastic layer is represented using fractional derivatives and the Grünwald approximation. The extended Hamilton's principle is used to derive the system governing equations which are integrated with the Newmark time-integration system.

scholarly journals A quasi-two-dimensional finite element formulation for analysis of active-passive constrained layer beams

2021 ◽  
Author(s):  
Jean-Jacques R. Boiluea Bekuit
Keyword(s):  
Finite Element ◽  
Piezoelectric Layer ◽  
Layer Structure ◽  
Time Integration ◽  
Beam Theory ◽  
Viscoelastic Layer ◽  
Element Formulation ◽  
Transverse Displacement ◽  
Passive Damping ◽  
Dimensional Finite Element

Active-passive damping is getting more popular with designers because it combines the complementary passive and active features in the control of structural vibrations. The classical three-layer structure has a viscoelastic-layer sandwiched between the host beam and a piezoelectric-layer. The more prevalent assumptions for modeling the system are the use of Euler-Bernoulli beam theory for both the host beam and piezoelectric-layer, and Timoshenko beam theory for the viscoelastic-layer. The assumption that transverse displacement is constant through the thickness limits accuracy and applicability of the model. The current formulation expresses the through-the-thickness dependency of the field variables as polynomials while their span dependency across a finite element is cubically interpolated. The versatility of the formulation is demonstrated via static and dynamic studies of examples taken from the literature. A beam treated with active-passive damping is presented and examined. The constitutive relation of the viscoelastic layer is represented using fractional derivatives and the Grünwald approximation. The extended Hamilton's principle is used to derive the system governing equations which are integrated with the Newmark time-integration system.

scholarly journals A Finite Element Formulation Of Active Constrained-Layer Functionally Graded Beam

2021 ◽  
Author(s):  
Ry Long
Keyword(s):  
Layer Structure ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Functionally Graded ◽  
Viscoelastic Layer ◽  
Integration Scheme ◽  
Element Formulation ◽  
Constrained Layer Damping ◽  
Functionally Graded Beam ◽  
Active Constrained Layer

Active constrained-layer damping (ACLD) treatment is the combination of passive and active features in the control of structural vibrations. A three-layer structure that consists of a functionally graded (FG) host beam, with a bonded viscoelastic layer and a constraining piezoelectric fiber-reinforce composite (PFRC) laminate is modeled and analyzed. The assumptions for modeling the system are the application of Timoshenko beam theory for the host beam and PFRC laminate, and a higher-order beam theory for the viscoelastic layer. The formulation is assumed to have field variables that are expressed as polynomials through the thickness of the structure and linear interpolation across the span. The extended Hamilton's principle is utilized to determine the system equations of motion, which are then solved using the Newmark time-integration scheme. Many support conditions such as fully- and partial-clamped cantilevered, partially clamped-clamped and simply-supported are analyzed. The effects of ply angle orientaion, as well as FG properties, are also carefully examined.

Pontoon Torsional Strength Analysis Related to Ships with Large Deck Openings

1991 ◽  
Vol 35 (04) ◽  
pp. 339-351
Author(s):  
Ivo Senjanovic ◽  
Ying Fan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Middle Part ◽  
Strength Analysis ◽  
Element Formulation ◽  
Dimensional Finite Element ◽  
Torsional Analysis ◽  
Three Dimensional Finite Element

The torsional problem of a pontoon, consisting of channel middle part and rectangular tube peaks, isconsidered within the higher-order beam theory. The cross section and the contour compatibility conditions for assembling of the pontoon parts are investigated. The acceptability of the introduced assumptions is checked by three-dimensional finite-element model analysis. Some deficiencies of the classical beam theory regarding the girder stiffness are noticed. The finite-element formulation to be used for the torsional analysis of the ship's hull with large hatch openings is given.

scholarly journals A Finite Element Formulation Of Active Constrained-Layer Functionally Graded Beam

2021 ◽  
Author(s):  
Ry Long
Keyword(s):  
Layer Structure ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Functionally Graded ◽  
Viscoelastic Layer ◽  
Integration Scheme ◽  
Element Formulation ◽  
Constrained Layer Damping ◽  
Functionally Graded Beam ◽  
Active Constrained Layer

Active constrained-layer damping (ACLD) treatment is the combination of passive and active features in the control of structural vibrations. A three-layer structure that consists of a functionally graded (FG) host beam, with a bonded viscoelastic layer and a constraining piezoelectric fiber-reinforce composite (PFRC) laminate is modeled and analyzed. The assumptions for modeling the system are the application of Timoshenko beam theory for the host beam and PFRC laminate, and a higher-order beam theory for the viscoelastic layer. The formulation is assumed to have field variables that are expressed as polynomials through the thickness of the structure and linear interpolation across the span. The extended Hamilton's principle is utilized to determine the system equations of motion, which are then solved using the Newmark time-integration scheme. Many support conditions such as fully- and partial-clamped cantilevered, partially clamped-clamped and simply-supported are analyzed. The effects of ply angle orientaion, as well as FG properties, are also carefully examined.

scholarly journals A Kollár and Pluzsik anisotropic composite beam theory for arbitrary multicelled cross sections

2016 ◽  
Vol 35 (23) ◽  
pp. 1696-1711 ◽  
Author(s):  
Danilo S Victorazzo ◽  
Andre De Jesus
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Composite Beam ◽  
Linear Equations ◽  
Beam Theory ◽  
Element Formulation ◽  
Compliance Matrix ◽  
Asymmetric System ◽  
Anisotropic Composite ◽  
Stiffness Matrices

In this paper we extend Kollár and Pluzsik’s thin-walled anisotropic composite beam theory to include multiple cells with open branches and booms, and present a finite element formulation utilizing the stiffness matrix obtained from this theory. To recover the 4 × 4 compliance matrix of a beam containing N closed cells, we solve an asymmetric system of 2N + 4 linear equations four times with unitary section loads and extract influence coefficients from the calculated strains. Finally, we compare 4 × 4 stiffness matrices of a multicelled beam using this method against matrices obtained using the finite element method to demonstrate accuracy. Similarly to its originating theory, the effects of shear deformation and restrained warping are assumed negligible.

Lagrangian Finite Element Formulation to Axisymmetric Liquid Sloshing

2011 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
Tomohiko Tsuchida ◽  
Katsuki Iwata
Keyword(s):  
Finite Element ◽  
Axisymmetric Problem ◽  
Time Integration ◽  
Three Dimensional ◽  
Computer Code ◽  
Element Formulation ◽  
Liquid Storage ◽  
Analysis Technique ◽  
Lagrangian Finite Element ◽  
Spurious Modes

The sloshing analysis of liquid storage tanks by the finite element method is basically categorized into two approaches, Lagrangian approach and Eulerian approach. In the Lagragian approach, the behavior of the fluid is expressed in terms of the displacements at nodal points. The advantage of the Lagragian method is that the computer code can be easily developed to modify an existing structural analysis code. The disadvantage is that some spurious modes are included in the vibration modes. The Lagrangian method is widely used in two- and three-dimensional problems. On the other hand, it has not been reported its applicability to the axisymmetric problem. This paper presents the applicability of the Lagragian method to the axisymmetric sloshing problem. The eigenvalue of an elemental stiffness matrix is analyzed in order to investigate the characteristics of the rotational stiffness to the compressibility of the fluid. As a result, this method is found to be difficult to apply to the axisymmetric problem if the equation of motion is directly solved using time integration. However, it gives the highly precise response solutions if the only sloshing modes are taken out and the modal analysis technique is used.

Shear-deformable hybrid finite-element formulation for lateral-torsional buckling analysis of composite thin-walled members

2020 ◽  
Author(s):  
Emre Erkmen ◽  
Vida Niki ◽  
Ashkan Afnani
Keyword(s):  
Finite Element ◽  
Beam Theory ◽  
Buckling Analysis ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Hybrid Finite Element ◽  
Thin Walled ◽  
Shear Deformable

A shear deformable hybrid finite element formulation is developed for the lateral-torsional buckling analysis of fiber-reinforced composite thin-walled members with open cross-section. The method is developed by using the Hellinger-Reissner functional. Comparison to the displacement-based formulations the current hybrid formulation has the advantage of incorporating the shear deformation effects easily by using the strain energy of the shear stress field without modifying the basic kinematic assumptions of the thin-walled beam theory. Numerical results are validated through comparisons with results based on other formulations presented in the literature. Examples illustrate the effects of shear deformations and stacking sequence of the composite layers in predicting bucking loads.

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