Impact of the vibration measurement points geometric coordinates uncertainties on two-dimensional k-space identification: Application to a sandwich plate with honeycomb core

When comparing composite sandwich analysis with an exact solution, the results of finite element modeling with an ANSYS shell 91 element agreed well with the exact solution. The practical applications of the shell 91 element are demonstrated with a four-point bend test conducted on sandwich beam specimens. The specimens comprised carbon/epoxy fabric face sheets and a honeycomb core. Two kinds of honeycomb cores were used to fabricate the composite sandwich specimens: an aluminum one and a glass/phenolic one. The predictions with the shell 91 element were also agreed well with the experimental results. A variety of tests was conducted; namely, a long beam flexural test, a short beam shear test, a flatwise tensile test, a flatwise compression test and an edge compression test. The sandwich plate with the aluminum honeycomb core had a specific bending stiffness that was 1.7 to 2.0 times higher than that of the sandwich plate with the glass/ phenolic honeycomb core.

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Nonlinear oscillations of a sandwich plate with a 3D-printed honeycomb core

Technical mechanics ◽

10.15407/itm2021.04.104 ◽

2021 ◽

Vol 2021 (4) ◽

pp. 104-117

Author(s):

K.V. Avramov ◽

◽

B.V. Uspensky ◽

I.I. Derevianko ◽

◽

...

Keyword(s):

Finite Element ◽

Frequency Response ◽

Finite Element Simulation ◽

Sandwich Plate ◽

Nonlinear Oscillations ◽

Ritz Method ◽

Forced Oscillations ◽

Homogeneous Layer ◽

Honeycomb Core ◽

Element Simulation

A three-layer sandwich plate with a FDM-printed honeycomb core made of polycarbonate is considered. The upper and lower faces of the sandwich are made of a carbon fiber-reinforced composite. To study the response of the sandwich plate, the honeycomb core is replaced with a homogeneous layer with appropriate mechanical properties. To verify the honeycomb core model, a finite-element simulation of the representative volume of the core was performed using the ANSYS software package. A modification of the high-order shear theory is used to describe the structure dynamics. The assumed-mode method is used to simulate nonlinear forced oscillations of the plate. The Rayleigh–Ritz method is used to calculate the eigenfrequencies and eigenmodes of the plate, in which the displacement of the plate points during nonlinear oscillations are expanded. This technique allows one to obtain a finite-degree-of-freedom nonlinear dynamic system, which describes the oscillations of the plate. The frequency response of the system is calculated using the continuation approach applied to a two-point boundary value problem for nonlinear ordinary differential equations and the Floquet multiplier method, which allows one to determine the stability and bifurcations of periodic solutions. The resonance behavior of the system is analyzed using its frequency response. The proposed technique is used to analyze the forced oscillations of a square three-layer plate clamped along the contour. The results of the analysis of the free oscillations of the plate are compared with those of ANSYS finite-element simulation, and the convergence of the results with increasing number of basis functions is analyzed. The comparison shows that the results are in close agreement. The analysis of the forced oscillations shows that the plate executes essentially nonlinear oscillations with two saddle-node bifurcations in the frequency response curve, in which the periodic motion stability of the system changes. The nonlinear oscillations of the plate near the first fundamental resonance are mostly monoharmonic. They may be calculated using the describing function method.

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Influence of the Honeycomb Geometry on the Sandwich Composite Plate Behavior

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1143.139 ◽

2017 ◽

Vol 1143 ◽

pp. 139-144 ◽

Cited By ~ 4

Author(s):

Florentina Rotaru ◽

Ionel Chirica ◽

Elena Felicia Beznea

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Sandwich Plate ◽

Compressive Loading ◽

Sandwich Composite ◽

Orthotropic Materials ◽

Honeycomb Core ◽

Element Analysis ◽

Composite Sandwich ◽

The Impact

In this paper the influence cell honeycomb geometry on the mechanical behaviour of a composite sandwich plate is analyzed. Three cell geometries (circular, hexagonal and square) are static analysed so that to select the best type of honeycomb that will be used in the manufacturing the sandwich plate core. The main aim is to develop approach models of equivalent orthotropic materials to replace the real model of honeycomb core with their properties so that to quickly calculate the sandwich plate made out of composite when is used a finite element analysis code. Geometry and material properties of the honeycomb are delivered by the material provider. Comparative analysis, by using Finite element analysis is performed for all geometries, in the same boundary conditions. Since in the impact loading of the composite sandwich plate the core is mainly loaded to compression, comparative study of the three cell geometries honeycomb was performed for this type of compressive loading. Since the cell is the basic element of the honeycomb core, the calculus is performed for one unit volume of sandwich, concerning also the part of skins.

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FPGA based self-vibration compensated two dimensional non-contact vibration measurement using 2D position sensitive detector with remote monitoring

Measurement ◽

10.1016/j.measurement.2017.07.038 ◽

2017 ◽

Vol 111 ◽

pp. 271-278 ◽

Cited By ~ 5

Author(s):

Ardhendu Saha ◽

Sampa Das ◽

M. Suresh ◽

V. Raj Kiran ◽

Naiwrita Dey

Keyword(s):

Remote Monitoring ◽

Position Sensitive Detector ◽

Vibration Measurement ◽

Two Dimensional ◽

Sensitive Detector ◽

Position Sensitive

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The Vibration of an Internally Damped Sandwich Plate Radiating Into a Fluid Medium

Journal of Engineering for Industry ◽

10.1115/1.3670849 ◽

1965 ◽

Vol 87 (3) ◽

pp. 379-384 ◽

Cited By ~ 1

Author(s):

I. W. Jones ◽

V. L. Salerno

Keyword(s):

Sandwich Plate ◽

Internal Damping ◽

Damping Properties ◽

Pressure Loading ◽

Honeycomb Core ◽

Fluid Medium ◽

At Resonance ◽

Time Harmonic ◽

Honeycomb Sandwich ◽

Aluminum Honeycomb

An analysis is given for the vibration of a long sandwich plate with linear internal damping properties. The plate is subjected to a time-harmonic pressure loading of constant amplitude and is considered vibrating both in vacuo and in an environment consisting of vacuum on one side and a fluid medium on the other. Numerical results are presented for both a conventional and a highly damped sandwich plate. The conventional (aluminum honeycomb) sandwich plate produces only a small amount of damping, but when the honeycomb core is replaced by a highly dissipative thermoplastic, the maximum deflection and stress at resonance are reduced theoretically by about two orders of magnitude.

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Wide-field heterodyne interferometric vibrometry for two-dimensional surface vibration measurement

Optics Communications ◽

10.1016/j.optcom.2015.08.016 ◽

2015 ◽

Vol 356 ◽

pp. 343-349 ◽

Cited By ~ 6

Author(s):

Samuel Choi ◽

Yuta Maruyama ◽

Takamasa Suzuki ◽

Fumiaki Nin ◽

Hiroshi Hibino ◽

...

Keyword(s):

Vibration Measurement ◽

Wide Field ◽

Two Dimensional ◽

Surface Vibration ◽

Dimensional Surface

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Two-dimensional optical coherence vibration tomography for low-frequency vibration measurement and response-only modal analysis

Mechanical Systems and Signal Processing ◽

10.1016/j.ymssp.2016.02.027 ◽

2016 ◽

Vol 79 ◽

pp. 65-71 ◽

Cited By ~ 6

Author(s):

Jianfeng Zhong ◽

Shuncong Zhong ◽

Qiukun Zhang

Keyword(s):

Modal Analysis ◽

Low Frequency ◽

Vibration Measurement ◽

Optical Coherence ◽

Two Dimensional ◽

Low Frequency Vibration

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Vibration and Flutter of a Honeycomb Sandwich Plate with Zero Poisson’s Ratio

Mathematics ◽

10.3390/math9192528 ◽

2021 ◽

Vol 9 (19) ◽

pp. 2528

Author(s):

Junhua Zhang ◽

Zhaochen Yan ◽

Lili Xia

Keyword(s):

Poisson’S Ratio ◽

Sandwich Plate ◽

Natural Frequencies ◽

Free Vibrations ◽

Geometric Parameters ◽

Poisson's Ratio ◽

Honeycomb Core ◽

Honeycomb Sandwich ◽

Honeycomb Sandwich Plate ◽

Honeycomb Cores

A honeycomb is a kind of excellent lightweight structure and a honeycomb sandwich plate with zero Poisson’s ratio (ZPR) core is used widely in morphing structures. In this paper, a sandwich plate composed of a honeycomb core with zero Poisson’s ratio is analyzed for free vibrations and flutter under supersonic airflows. The equivalent elastic parametric formulas of the honeycomb core for zero Poisson’s ratio are proposed. The models are compared for their natural frequencies by theoretical and finite element methods respectively, which verifies the validity of the equivalent elastic parametric formulas and the model for the honeycomb sandwich plate with zero Poisson’s ratio. The influence of the geometric parameters of the honeycomb plate on the vibration frequencies is obtained. Three kinds of honeycomb cores, namely, regular hexagon, auxetic and hybrid with zero Poisson’s ratio, are compared through natural frequencies of the sandwich plate. It is found that the frequency of the zero Poisson’s ratio honeycomb sandwich plate is the second one when the other parameters are the same. The flutter of the honeycomb plate is analyzed by using the first order piston theory under supersonic flows. The critical flutter velocity of the plate is obtained, and the influence of geometric parameters of the honeycomb plate on the critical flutter velocities is obtained.

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