Sandwich Beams With Corrugated and Y-frame Cores: Does the Back Face Contribute to the Bending Response?

2011 ◽  
Vol 79 (1) ◽  
Author(s):  
L. St-Pierre ◽  
N. A. Fleck ◽  
V. S. Deshpande
Keyword(s):  
Three Dimensional ◽  
Sandwich Panels ◽  
Equal Mass ◽  
Front Face ◽  
Sandwich Beams ◽  
Fe Method ◽  
Plastic Buckling ◽  
Three Point Bending ◽  
Simply Supported ◽  
Back Face

Stainless steel sandwich beams with a corrugated core or a Y-frame core have been tested in three-point bending and the role of the face-sheets has been assessed by considering beams with (i) front-and-back faces present, and (ii) front face present but back face absent. A fair comparison between competing beam designs is made on an equal mass basis by doubling the front face thickness when the back face is absent. The quasi-static, three-point bending responses were measured under simply supported and clamped boundary conditions. For both end conditions and for both types of core, the sandwich beams containing front-and-back faces underwent indentation beneath the mid-span roller whereas Brazier plastic buckling was responsible for the collapse of sandwich beams absent the back face. Three-dimensional finite element (FE) predictions were in good agreement with the measured responses and gave additional insight into the deformation modes. The FE method was also used to study the effect of (i) mass distribution between core and face-sheets and (ii) beam span upon the collapse response of a simply supported sandwich panel. Sandwich panels of short span are plastically indented by the mid-span roller and the panels absent a back face are stronger than those with front-and-back faces present. In contrast, sandwich panels of long span undergo Brazier plastic buckling, and the presence of a back face strengthens the panel.

Impact Analysis of Honeycomb Core Sandwich Panels

2020 ◽  
Author(s):  
Shah Alam ◽  
Damodar Khanal
Keyword(s):  
Sandwich Panels ◽  
Sheet Thickness ◽  
Composite Panel ◽  
Face Sheet ◽  
Impact Behavior ◽  
Front Face ◽  
Geometrical Parameters ◽  
Honeycomb Core ◽  
Back Face ◽  
The Impact

Abstract The goal of this paper is to analyze the impact behavior among geometrically different sandwich panels shown upon impact velocities. Initially, composite model with aluminum honeycomb core and Kevlar (K29) face sheets is developed in ABAQUS/Explicit and different impact velocities are applied. Keeping other parameters constant, model is simulated with T800S/epoxy face sheets. Residual velocities, energy absorption (%), and maximum deformation depth is calculated for sandwich panel for both models at five different velocities by executing finite element analysis. Once the better material is found for face sheets, process is extended by varying the ratio of front face sheet thickness to back face sheet thickness keeping other geometrical parameters constant to find the better geometry. Also, comparison of impact responses of sandwich composite panel on different ratio of front face sheet thickness to back face sheet thickness is done and validated with other results available in literature.

Experimental Study of Sandwich Panels Subjected to Foam Projectile Impact

2013 ◽  
Vol 535-536 ◽  
pp. 501-504
Author(s):  
Mohd Azman Yahaya ◽  
Dong Ruan ◽  
Guo Xing Lu
Keyword(s):  
Metal Foam ◽  
Impact Load ◽  
Sandwich Panels ◽  
Equal Mass ◽  
Aluminium Foam ◽  
Element Analysis ◽  
Measuring Device ◽  
Back Face ◽  
History Of ◽  
The Impact

Similar blast loading characteristics can be obtained using impact of aluminium foam projectiles, which enables blast tests to be mimicked in a laboratory scale and in a safer environment. The purpose of this study is to determine the back-face deflection history of aluminium sandwich panels experimentally by aids of a laser displacement meter when panels are subjected to the impact of metal foam projectiles. This information was usually determined using finite element analysis (FEA) due to the difficulty in the experiment. The projectiles are cylindrical ALPORAS aluminium foam with diameter of 37 mm, length of 50 mm and nominal relative density of 10%. The sandwich panels consist of two 1 mm aluminium face-sheets and an aluminium honeycomb as the core. There are five different core configurations with a brand name of HEXCEL. The projectiles are fired towards the centre of the sandwich panels at different velocities using a gas gun. During the tests, a laser optical displacement measuring device is used to record the history of the back-face deflection experimentally. The deflection of the back-face is found to reach the maximum before coming to rest at a smaller value. The final back-face deflections of the sandwich panels show exponential relationship with the projectile impulse. The final deflections are compared with the deflection of monolithic plates with equal mass. The sandwich panels deflect less than the monolithic plate with an equal mass up to a critical value but continue to increase significantly afterwards. Care should be taken when using sandwich panels as protective structures against foam projectiles as beyond this point, the monolithic plates outperform the sandwich panels in absorbing the impact load.

Numerical Study on the Response of Functionally Graded PVC Foam Core Sandwich Panels Subjected to Non-Contact Underwater Explosion

2018 ◽  
Author(s):  
Tianyu Zhou ◽  
Pan Zhang ◽  
Yuansheng Cheng ◽  
Manxia Liu ◽  
Jun Liu
Keyword(s):  
Sandwich Panel ◽  
Blast Resistance ◽  
Sandwich Panels ◽  
Underwater Explosion ◽  
Functionally Graded ◽  
Front Face ◽  
Foam Core ◽  
Compression Phase ◽  
The Core ◽  
Back Face

In this paper, the numerical model was developed by using the commercial code LS/DYNA to investigate the dynamic response of sandwich panels with three PVC foam core layers subjected to non-contact underwater explosion. The simulation results showed that the structural response of the sandwich panel could be divided into four sequential regimes: (1) interaction between the shock wave and structure, (2) compression phase of sandwich core, (3) collapse of cavitation bubbles and (4) overall bending and stretching of sandwich panel under its own inertia. Main attention of present study was placed at the blast resistance improvement by tailoring the core layer gradation under the condition of same weight expense and same blast load. Using the minimization of back face deflection as the criteria for evaluating the blast resistant of panel, the panels with core gradation of high/middle/low or middle/low/high (relative densities) from the front face to back face demonstrated the optimal resistance. Moreover, the comparative studies on the blast resistance of the functionally graded sandwich panels and equivalent ungraded ones were carried out. The optimum functionally graded sandwich panel outperformed the equivalent ungraded one for relatively small charge masses. The energy absorption characteristics as well as the core compression were also discussed. It is found that the core gradation has a negligible effect on the whole energy dissipation of panel, but would significantly affect the energy distribution among sandwich panel components and the compression value of core.

scholarly journals Numerical Analysis of Dynamic Response of Corrugated Core Sandwich Panels Subjected to Near-Field Air Blast Loading

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Pan Zhang ◽  
Yuansheng Cheng ◽  
Jun Liu
Keyword(s):  
Dynamic Response ◽  
Failure Modes ◽  
Near Field ◽  
Three Dimensional ◽  
Sandwich Panels ◽  
Blast Loading ◽  
Front Face ◽  
Air Blast ◽  
Solid Plate ◽  
Air Blast Loading

Three-dimensional fully coupled simulation is conducted to analyze the dynamic response of sandwich panels comprising equal thicknesses face sheets sandwiching a corrugated core when subjected to localized impulse created by the detonation of cylindrical explosive. A large number of computational cases have been calculated to comprehensively investigate the performance of sandwich panels under near-field air blast loading. Results show that the deformation/failure modes of panels depend strongly on stand-off distance. The beneficial FSI effect can be enhanced by decreasing the thickness of front face sheet. The core configuration has a negligible influence on the peak reflected pressure, but it has an effect on the deflection of a panel. It is found that the benefits of a sandwich panel over an equivalent weight solid plate to withstand near-field air blast loading are more evident at lower stand-off distance.

AN EXPERIMENTAL AND PRELIMINARY ANALYTICAL STUDY ON THE IMPULSE RESPONSE OF METALLIC SANDWICH PANELS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1337-1342
Author(s):  
FENG ZHU ◽  
LONGMAO ZHAO ◽  
GUOXING LU ◽  
ZHIHUA WANG
Keyword(s):  
Analytical Study ◽  
Empirical Equation ◽  
Sandwich Panels ◽  
Structural Response ◽  
Systematic Investigation ◽  
Front Face ◽  
Failure Patterns ◽  
Impulsive Loads ◽  
Back Face ◽  
Quantitative Results

To investigate the structural response of sandwich panels loaded by impulsive loads, a systematic investigation has been conducted, and some experimental results are reported and discussed in this paper. Quantitative results were obtained based on the measurement in the tests by a pendulum with corresponding sensors, and then the deformation/failure patterns of front face and core were classified and analyzed systematically. Finally, an empirical equation is proposed to predict the back face deflection of the panels.

Dynamic Compressive Response of Stainless-Steel Square Honeycombs

2006 ◽  
Vol 74 (4) ◽  
pp. 658-667 ◽  
Author(s):  
D. D. Radford ◽  
G. J. McShane ◽  
V. S. Deshpande ◽  
N. A. Fleck
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Three Dimensional ◽  
Rate Sensitivity ◽  
Front Face ◽  
Plastic Wave ◽  
Compressive Response ◽  
Back Face ◽  
Three Dimensional Finite Element ◽  
The Impact

The dynamic out-of-plane compressive response of stainless-steel square honeycombs has been investigated for impact velocities ranging from quasi-static values to 300ms−1. Square-honeycomb specimens of relative density 0.10 were manufactured using a slotting technique, and the stresses on the front and back faces of the dynamically compressed square honeycombs were measured using a direct impact Kolsky bar. Three-dimensional finite element simulations of the experiments were performed to model the response and to help interpret the experimental results. The study has identified three distinct factors governing the dynamic response of the square honeycombs: material rate sensitivity, inertial stabilization of the webs against buckling, and plastic wave propagation. Material rate sensitivity and inertial stabilization of the webs against buckling cause the front and back face stresses to increase by about a factor of two over their quasi-static value when the impact speed is increased from 0 to 50ms−1. At higher impact velocities, plastic wave effects cause the front face stress to increase linearly with velocity whereas the back face stress is almost independent of velocity. The finite element predictions are in reasonable agreement with the measurements.

Analysis of Interface Deformation of Steel-Concrete-Steel Sandwich Beam

2012 ◽  
Vol 525-526 ◽  
pp. 357-360
Author(s):  
Pei Xiu Xia ◽  
Guang Ping Zou ◽  
Zhong Liang Chang
Keyword(s):  
Sandwich Beam ◽  
Analytical Models ◽  
Sandwich Beams ◽  
Interface Deformation ◽  
Simply Supported ◽  
Interface Slip ◽  
Steel Panels ◽  
Uniformly Distributed Loads ◽  
Relationship Of ◽  
The Relationship

The effect of the interface slip is neglected in most studies on calculating deflection of sandwich beams. By taking a simply supported sandwich beams under uniformly distributed loads as an example, simplified analytical models of the interface slip are established, and corresponding clculation formulas of interface slip between steel panels and concrete and section curvatures are derived. The formula for deflection of sandwich beams are then presented. This formula reflects the relationship of influence each other between the interface slip and deflection.

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

Sign in / Sign up

Export Citation Format

Share Document