Combined Compression-Shear Behavior of Aluminum Honeycombs

2014 ◽  
Vol 626 ◽  
pp. 127-132 ◽  
Author(s):  
Asm Ashab ◽  
Dong Ruan ◽  
Guo Xing Lu ◽  
Yat C. Wong
Keyword(s):  
Mechanical Response ◽  
Indentation Load ◽  
Shear Loading ◽  
Plane Orientation ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
Good Energy ◽  
Plane Direction ◽  
Crushing Behavior ◽  
Naval Engineering

Aluminum honeycombs are lightweight and have good energy absorption capability. They are widely used in industrial products and also as core materials in various fields of engineering such as aerospace, automotive and naval engineering because of their high specific strengths and they can undergo large plastic deformation to absorb high impact energy. In the applications of aluminum honeycombs they are not only subjected to pure compressive or indentation load but sometime also under combined compression-shear load. The mechanical response and crushing behavior under combined compression-shear loading condition is still limited in literature. In this paper, quasi-static out-of-plane combined compression-shear tests were conducted to study the deformation mechanism of different types of HEXCELL® aluminum honeycombs with different cell sizes and wall thicknesses. Three types of aluminum honeycombs were used in this study. A universal MTS machine with specially designed fixtures was employed in the quasi-static loading tests. The experiments were conducted at three different loading angles, that is, 30°, 45° and 60° and in TL and TW (T is out-of-plane direction and L, W are the two in-plane directions) plane orientation loading directions of aluminum honeycomb. The effects of different loading angle and different plane orientation are reported in this experimental study. Similarly, the effects of cell size and cell wall thickness were also analyzed.

Experimental and Finite Element Based Investigations of In-Plane and Out-of-Plane Properties of Aluminum Honeycomb

2013 ◽  
Vol 275-277 ◽  
pp. 111-116 ◽  
Author(s):  
Muhammad Kashif Khan ◽  
Qing Yuan Wang
Keyword(s):  
Finite Element ◽  
Sample Size ◽  
Cell Size ◽  
Mechanical Response ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
Plane Direction ◽  
Honeycomb Cores

Experimental and Finite Element analysis was used for the investigation of the effect of cell size and thickness on the compressive properties of Aluminium honeycomb core. Honeycomb cores were compressed experimentally in in-plane and out of plane directions. The effect of sample size, cell size and thickness on the elastic modulus, yield strength and plateau stress was investigated through FEA. It was found that the mechanical response was independent upon the sample size in in-plane direction. The smallest cell size honeycomb core was deformed at higher yield stress. Similarly, with increase in cell wall thickness, the modulus of the core increased.

scholarly journals Inserting Stress Analysis of Combined Hexagonal Aluminum Honeycombs

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Xiangcheng Li ◽  
Kang Li ◽  
Yuliang Lin ◽  
Rong Chen ◽  
Fangyun Lu
Keyword(s):  
Structural Parameters ◽  
Base Material ◽  
Peak Stress ◽  
Displacement Curve ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
The One ◽  
Absorbing Property ◽  
Crushing Behavior ◽  
Energy Absorbing

Two kinds of hexagonal aluminum honeycombs are tested to study their out-of-plane crushing behavior. In the tests, honeycomb samples, including single hexagonal aluminum honeycomb (SHAH) samples and two stack-up combined hexagonal aluminum honeycombs (CHAH) samples, are compressed at a fixed quasistatic loading rate. The results show that the inserting process of CHAH can erase the initial peak stress that occurred in SHAH. Meanwhile, energy-absorbing property of combined honeycomb samples is more beneficial than the one of single honeycomb sample with the same thickness if the two types of honeycomb samples are completely crushed. Then, the applicability of the existing theoretical model for single hexagonal honeycomb is discussed, and an area equivalent method is proposed to calculate the crushing stress for nearly regular hexagonal honeycombs. Furthermore, a semiempirical formula is proposed to calculate the inserting plateau stress of two stack-up CHAH, in which structural parameters and mechanics properties of base material are concerned. The results show that the predicted stresses of three kinds of two stack-up combined honeycombs are in good agreement with the experimental data. Based on this study, stress-displacement curve of aluminum honeycombs can be designed in detail, which is very beneficial to optimize the energy-absorbing structures in engineering fields.

A Computational Study on Residual Strength of Sandwich Composite Panel

2011 ◽  
Vol 393-395 ◽  
pp. 521-525 ◽  
Author(s):  
Sang Kyo Lee ◽  
Mohd. Zahid Ansari ◽  
Na Wang ◽  
Chong Du Cho
Keyword(s):  
Residual Strength ◽  
Computational Study ◽  
Static Condition ◽  
Composite Panel ◽  
Sandwich Composite ◽  
Element Analysis ◽  
Reinforced Plastic ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
Plane Direction

The present study investigates numerically the compressive residual strength of indented sandwich composite panel. The composite is made of carbon fiber reinforced plastic (CFRP) face sheets and aluminum honeycomb core. The sandwich is loaded under quasi-static condition and along out-of-plane direction. A commercial finite element analysis software ABAQUS is used. The results show that the indented composite retains significant amount of strength after indentation. And, the post-indentation strength of the composite is about 65% its pre-indentation strength under compression.

Analysis of Mechanical Response of Aluminum Honeycomb Subjected to Indentation

2014 ◽  
Author(s):  
A. S. M. Ashab ◽  
Dong Ruan ◽  
Guoxing Lu ◽  
Yat Choy Wong
Keyword(s):  
Numerical Analysis ◽  
High Speed ◽  
Mechanical Response ◽  
Strain Curve ◽  
Deformation Mode ◽  
Plateau Stress ◽  
Aluminum Honeycomb ◽  
Good Energy ◽  
Curve Profile ◽  
Honeycomb Cell

Aluminium honeycombs is a lightweight cellular material and a good energy absorber. In different engineering applications, it is usually used as structural components. Comprehensive study has been conducted to analyse the compressive behaviour of aluminium honeycombs. However, research related to mechanical response of aluminium honeycombs material subjected to different type of loadings, such as indentation, is still limited. In this paper, experimental and numerical studies were conducted to investigate the deformation mechanism and energy dissipation of a HEXCELL® aluminium honeycomb subjected to dynamic indentation. A high speed INSTRON machine was used to conduct dynamic tests at velocities of 0.5 m/s and 5 m/s. Numerical analysis was conducted using ANSYS LS-DYNA at velocities of 5 m/s, 15 m/s and 25 m/s. The simulation results were in good agreement with the experimental results in terms of stress-strain curve profile and deformation mode. In the experiment, it was found that with the increase of velocity (strain rate) the average plateau stress of indentation also increases which was validated in the numerical analysis. The deformation of aluminium honeycombs under indentation showed that the compression of hexagonal honeycomb cells under the indenter and also tearing of honeycomb cell walls along the four edges of the indenter. The dissipation of energy in compression and tearing was calculated and discussed. The effect of loading velocity on the plateau stress and energy absorption was also analyzed.

scholarly journals Mechanical response and strength characteristics of aluminum honeycomb sandwich panels for infrastructure engineering

2021 ◽  
Vol 1201 (1) ◽  
pp. 012046
Author(s):  
S P Zaoutsos
Keyword(s):  
Mechanical Behaviour ◽  
Mechanical Response ◽  
Sandwich Panels ◽  
Strength Characteristics ◽  
Analytical Models ◽  
Three Point Bending ◽  
Aluminum Honeycomb ◽  
Experimental Findings ◽  
Naval Engineering ◽  
Intensive Work

Abstract The use of aluminium sandwich panels has been increased in a certain number of engineering applications from infrastructure systems and transportation to aircraft and naval engineering. Due to their structural efficiency these materials are ideal for applications where ratio of strength to weight is of crucial importance. In the current study the investigation of the strength characteristics of aluminium sandwich panels with aluminium honeycomb core and different types of skins is performed using both analytical models and experimental procedures. A series of strength tests such as tension, shear, three point bending and double cantilever beam were conducted on aluminium honeycomb-cored sandwich panel specimens with five different skins in order to examine the mode of failure and the mechanical behaviour of the structural elements. The experimental findings are compared to theoretical values while an attempt for the explanation of the mechanisms leading to failure such as buckling, delamination or debonding between core and skins is performed. The results occurring from the study are very useful for the enhancement of the mechanical behaviour of sandwich constructions, thus more intensive work must be carried out in order to understand the physical mechanisms leading to strength characteristics of sandwich panels.

Mechanism of the Transition From In-Plane Buckling to Helical Buckling for a Stiff Nanowire on an Elastomeric Substrate

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Youlong Chen ◽  
Yong Zhu ◽  
Xi Chen ◽  
Yilun Liu
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Stretchable Electronics ◽  
Buckling Mode ◽  
Design And Optimization ◽  
Out Of Plane ◽  
Plane Direction ◽  
Plane Displacement ◽  
Helical Buckling ◽  
Selection Of

In this work, the compressive buckling of a nanowire partially bonded to an elastomeric substrate is studied via finite-element method (FEM) simulations and experiments. The buckling profile of the nanowire can be divided into three regimes, i.e., the in-plane buckling, the disordered buckling in the out-of-plane direction, and the helical buckling, depending on the constraint density between the nanowire and the substrate. The selection of the buckling mode depends on the ratio d/h, where d is the distance between adjacent constraint points and h is the helical buckling spacing of a perfectly bonded nanowire. For d/h > 0.5, buckling is in-plane with wavelength λ = 2d. For 0.27 < d/h < 0.5, buckling is disordered with irregular out-of-plane displacement. While, for d/h < 0.27, buckling is helical and the buckling spacing gradually approaches to the theoretical value of a perfectly bonded nanowire. Generally, the in-plane buckling induces smaller strain in the nanowire, but consumes the largest space. Whereas the helical mode induces moderate strain in the nanowire, but takes the smallest space. The study may shed useful insights on the design and optimization of high-performance stretchable electronics and three-dimensional complex nanostructures.

scholarly journals Comparison of Induced Deflection and Forces in Piles Adjacent to Tunnelling and Deep Excavation in 2D and 3D Problems

2018 ◽  
Vol 203 ◽  
pp. 04011
Author(s):  
Ong Yin Hoe ◽  
Hisham Mohamad
Keyword(s):  
Bending Moment ◽  
Pile Group ◽  
3D Models ◽  
Deep Excavation ◽  
Pile Groups ◽  
Out Of Plane ◽  
National University ◽  
Plane Direction ◽  
2D And 3D ◽  
2D Model

There is a trend in Malaysia and Singapore, engineers tend to model the effect of TBM tunneling or deep excavation to the adjacent piles in 2D model. In the 2D model, the pile is modelled using embedded row pile element which is a 1-D element. The user is allowed to input the pile spacing in out-of-plane direction. This gives an impression to engineers the embedded pile row element is able to model the pile which virtually is a 3D problem. It is reported by Sluis (2014) that the application of embedded pile row element is limited to 8D of pile length. It is also reported that the 2D model overestimates the axial load in pile and the shear force and bending moment at pile top and it is not realistic in comparison to 3D model. In this paper, the centrifuge results of single pile and 6-pile group - tunneling problem carried out in NUS (National University of Singapore) are back-analysed with Midas GTS 3D and a 2D program. In a separate case study, pile groups adjacent to a deep excavation is modelled by 3D and 2D program. This paper compares the deflection and forces in piles in 2D and 3D models.

Magnetic quantum oscillations in doped antiferromagnets

2017 ◽  
Vol 31 (25) ◽  
pp. 1745015
Author(s):  
V. V. Kabanov
Keyword(s):  
Magnetic Field ◽  
Polar Angle ◽  
Two Dimensional ◽  
Plane Angle ◽  
Arbitrary Direction ◽  
Magnetization Direction ◽  
Quantum Oscillations ◽  
Out Of Plane ◽  
Plane Direction ◽  
Magnetic Quantum Oscillations

Energy spectrum of electrons (holes) doped into two-dimensional (2D) antiferromagnetic (AF) semiconductors is quantized in an external magnetic field of arbitrary direction. A peculiar dependence of de Haas–van Alphen (dHvA) magneto-oscillation amplitudes on the azimuthal in-plane angle from the magnetization direction and on the polar angle from the out-of-plane direction is found. The angular dependence of the amplitude is different if the measurements are performed in the field above and below of the spin-flop field.

Mechanical response of marble epistyles under shear: numerical analysis using an experimentally validated model

2018 ◽  
Vol 27 (3-4) ◽  
Author(s):  
Ermioni D. Pasiou ◽  
Stavros K. Kourkoulis
Keyword(s):  
Numerical Model ◽  
Stress Field ◽  
Mechanical Response ◽  
Specific Problem ◽  
Shear Loading ◽  
Filling Material ◽  
Experimental Protocol ◽  
Loading Mode ◽  
Traditional Design ◽  
Simple Contact

AbstractThe mechanical response of the restored “connections” of the epistyles of the Parthenon Temple on the Acropolis of Athens is studied assuming that the interconnected epistyles are under shear loading mode. The study is implemented by taking advantage of a numerical model, properly validated on the basis of the data of a recent relative experimental protocol. The main difficulty while studying the specific problem is the co-existence of three materials of completely different mechanical behaviors, i.e. the brittle marble of the epistyles, the ductile titanium of the connector and the cement-based material filling the grooves of the marble in which the connector is placed. The interfaces of this three-material-complex are simulated as simple contact with friction, the coefficient of which is, also, experimentally determined. Taking advantage of the data provided by the numerical model the stress field developed in the connector and the surrounding marble volume is described. Moreover, the forces imposed by the connector on the surface of the groove are quantitatively determined. Furthermore, the model permits a quantitative comparison between the mechanical response of the interconnected epistyles in the presence or in the absence of the “relieving space”. It is definitely concluded that the alternative design of the “connections”, according to which a small portion of the connector’s web is left uncovered by the filling material (relieving space), offers serious advantages against the traditional design, in the direction of reducing the intensity of the stress field developed in the marble volume surrounding the connector, thus, contributing to the protection of the authentic building material of the monument in the case of overloading of the epistyles.

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