Iterative and Simplified Sandwich Beam Theory for Partially Composite Concrete Sandwich Wall Panels

Analytical formulation for the evaluation of frequency of CFRP sandwich beam with debond, following the split beam theory, generally underestimates the stiffness, as the contact between the honeycomb core and the skin during vibration is not considered in the region of debond. The validation of the present analytical solution for multiple-debond size is established through 3D finite element analysis, wherein geometry of honeycomb core is modeled as it is, with contact element introduced in the debond region. Nonlinear transient analysis is followed by fast Fourier transform analysis to obtain the frequency response functions. Frequencies are obtained for two types of model having single debond and double debond, at different spacing between them, with debond size up to 40% of beam length. The analytical solution is validated for a debond length of 15% of the beam length, and with the presence of two debonds of same size, the reduction in frequency with respect to that of an intact beam is the same as that of a single-debond case, when the debonds are well separated by three times the size of debond. It is also observed that a single long debond can result in significant reduction in the frequencies of the beam than multiple debond of comparable length.

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Flexural behavior of precast insulated sandwich wall panels: Full-scale tests and design implications

Engineering Structures ◽

10.1016/j.engstruct.2018.11.068 ◽

2019 ◽

Vol 180 ◽

pp. 750-761 ◽

Cited By ~ 5

Author(s):

Hetao Hou ◽

Kefan Ji ◽

Wenhao Wang ◽

Bing Qu ◽

Mingji Fang ◽

...

Keyword(s):

Full Scale ◽

Flexural Behavior ◽

Wall Panels ◽

Sandwich Wall ◽

Full Scale Tests

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Efficient Finite Element for Evaluation of Strain Concentrations in Concrete Coated Pipelines

Volume 3: Pipeline and Riser Technology; Ocean Space Utilization ◽

10.1115/omae2008-57373 ◽

2008 ◽

Cited By ~ 1

Author(s):

Svein Sævik ◽

Martin Storheim ◽

Erik Levold

Keyword(s):

Finite Element ◽

Numerical Study ◽

Sandwich Beam ◽

Beam Theory ◽

Material Model ◽

Body Motion ◽

Theoretical Formulation ◽

Concrete Material ◽

Non Linear ◽

Full Scale Tests

MARINTEK has developed software for detailed analysis of pipelines during installation and operation. As part of the software development a new coating finite element was developed in cooperation with StatoilHydro enabling efficient analysis of field joint strain concentrations of long concrete coated pipeline sections. The element was formulated based on sandwich beam theory and application of the Principle of Potential Energy. Large deformations and non-linear geometry effects were handled by a Co-rotated “ghost” reference description where elimination of rigid body motion was taken care of by referring to relative displacements in the strain energy term. The non-linearity related to shear interaction and concrete material behaviour was handled by applying non-linear springs and a purpose made concrete material model. The paper describes the theoretical formulation and numerical studies carried out to verify the model. The numerical study included comparison between model and full-scale tests as well as between model and other commercial software. At last a 3000 m long pipeline was analysed to demonstrate the strain concentration behaviour of a concrete coated pipeline exposed to high temperature snaking on the seabed.

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Edgewise Bending Vibration Analysis of a Rotating Sandwich Beam with Magnetorheological Elastomer Core

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455418501341 ◽

2018 ◽

Vol 18 (11) ◽

pp. 1850134 ◽

Cited By ~ 3

Author(s):

S. Bornassi ◽

H. M. Navazi ◽

H. Haddadpour

Keyword(s):

Magnetic Field ◽

Layer Thickness ◽

Rectangular Cross Section ◽

Ritz Method ◽

Sandwich Beam ◽

Beam Theory ◽

Core Layer ◽

Magnetorheological Elastomer ◽

Bending Vibration ◽

Elastic Layers

The vibration of a rotating sandwich beam with magnetorheological elastomer (MRE) as a core between two elastic layers is theoretically analyzed in this paper. This study is focused on the bending vibration along the edgewise direction of a sandwich beam of rectangular cross-section, which, to the best of our knowledge, has not been addressed yet. The classical Euler–Bernoulli beam theory is used to model the dynamic behavior of the elastic layers. In the modeling, the effect of the MRE layer is considered by incorporating its shear strains and the inertia due to shear deformation and bending motion. The governing equations of motion of the rotating sandwich beam are derived by using the Ritz method and the Lagrange’s equations. The effects of the applied magnetic field, core layer thickness, rotational speed, setting angle and hub radius on the natural frequencies and the corresponding loss factors are investigated parametrically. The results show the significant effect of the magnetic field intensity and the MRE layer thickness on the modal characteristics of the MRE sandwich beam.

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Analytical and numerical investigation of the free vibration of functionally graded materials sandwich beams

Archives of Materials Science and Engineering ◽

10.5604/01.3001.0015.4314 ◽

2021 ◽

Vol 2 (110) ◽

pp. 72-85

Author(s):

S.H. Bakhy ◽

M. Al-Waily ◽

M.A. Al-Shammari

Keyword(s):

Analytical Solution ◽

Free Vibration ◽

Functionally Graded Materials ◽

Sandwich Beam ◽

Beam Theory ◽

Functionally Graded ◽

Gradient Index ◽

Sandwich Beams ◽

Graded Materials ◽

The Impact

Purpose: In this study, the free vibration analysis of functionally graded materials (FGMs) sandwich beams having different core metals and thicknesses is considered. The variation of material through the thickness of functionally graded beams follows the power-law distribution. The displacement field is based on the classical beam theory. The wide applications of functionally graded materials (FGMs) sandwich structures in automotive, marine construction, transportation, and aerospace industries have attracted much attention, because of its excellent bending rigidity, low specific weight, and distinguished vibration characteristics. Design/methodology/approach: A mathematical formulation for a sandwich beam comprised of FG core with two layers of ceramic and metal, while the face sheets are made of homogenous material has been derived based on the Euler–Bernoulli beam theory. Findings: The main objective of this work is to obtain the natural frequencies of the FG sandwich beam considering different parameters. Research limitations/implications: The important parameters are the gradient index, slenderness ratio, core metal type, and end support conditions. The finite element analysis (FEA), combined with commercial Ansys software 2021 R1, is used to verify the accuracy of the obtained analytical solution results. Practical implications: It was found that the natural frequency parameters, the mode shapes, and the dynamic response are considerably affected by the index of volume fraction, the ratio as well as face FGM core constituents. Finally, the beam thickness was dividing into frequent numbers of layers to examine the impact of many layers' effect on the obtained results. Originality/value: It is concluded, that the increase in the number of layers prompts an increment within the frequency parameter results' accuracy for the selected models. Numerical results are compared to those obtained from the analytical solution. It is found that the dimensionless fundamental frequency decreases as the material gradient index increases, and there is a good agreement between two solutions with a maximum error percentage of no more than 5%.

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