NUMERICAL STUDY OF BLAST-RESISTANT SANDWICH PANELS WITH ROTATIONAL FRICTION DAMPERS

2013 ◽  
Vol 13 (06) ◽  
pp. 1350014 ◽  
Author(s):  
WENSU CHEN ◽  
HONG HAO
Keyword(s):  
Energy Absorption ◽  
Sandwich Panel ◽  
Numerical Study ◽  
Blast Resistance ◽  
Sandwich Panels ◽  
Blast Loading ◽  
Blast Loads ◽  
Friction Damper ◽  
Energy Absorber ◽  
Blast Energy

Blast-resistant structures are traditionally designed with solid materials of huge weight to resist blast loads. This not only increases the construction costs, but also undermines the operational performance. To overcome these problems, many researchers develop new designs with either new materials or new structural forms, or both to resist the blast loads. Friction damper, as a passive energy absorber, has been used in earthquake-resistant design to absorb vibration energy from cyclic loading. The use of friction damper in blast-resistant design to absorb high-rate impact and blast energy, however, has not been well explored. This study introduces a new sandwich panel equipped with rotational friction hinge device with spring (RFHDS) between the outer and inner plates to resist the blast loading. This device RFHDS, as a special sandwich core and energy absorber, consists of rotational friction hinge device (RFHD) and spring. The RFHD is used to absorb blast energy while the spring is used to restore the original shape of the panel. This paper studies the mechanism of RFHD by using theoretical derivation and numerical simulations to derive its equivalent force–displacement relation and study its energy absorption capacity. In addition, the energy absorption and blast loading resistance capacities of the sandwich panel equipped with RFHDS are numerically investigated by using Ls-Dyna. It is found that the proposed sandwich panel can recover, at least partially its original configuration after the loading and thus maintain its operational and blast-resistance capability after a blasting event. In order to maximize the performance of the proposed sandwich panel, parametric calculations are carried out to study the performance of RFHDS and the sandwich panels with RFHDS. The best performing sandwich panel with RFHDS in resisting blast loadings is identified. This sandwich panel configuration might be employed to mitigate blast loading effects in structural sandwich panel design.

scholarly journals Dynamic Response and Optimal Design of Curved Metallic Sandwich Panels under Blast Loading

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Chang Qi ◽  
Shu Yang ◽  
Li-Jun Yang ◽  
Shou-Hong Han ◽  
Zhen-Hua Lu
Keyword(s):  
Dynamic Response ◽  
Energy Absorption ◽  
Sandwich Panel ◽  
Blast Resistance ◽  
Blast Loading ◽  
Outer Face ◽  
Air Blast ◽  
Blast Response ◽  
Artificial Neural Network Ann ◽  
Air Blast Loading

It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a “soft” outer face and a “hard” inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances.

scholarly journals A numerical study of the impact perforation of sandwich panels with graded hollow sphere cores

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao
Keyword(s):  
Boundary Conditions ◽  
Hollow Sphere ◽  
Sandwich Panel ◽  
Numerical Study ◽  
Sandwich Panels ◽  
Hopkinson Bar ◽  
Core Density ◽  
The Core ◽  
The Impact ◽  
Force Displacement

In this study, we numerically investigate the impact perforation of sandwich panels made of 0.8 mm 2024-T3 aluminum alloy skin sheets and graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using the LS-DYNA code, calibrated with an inverse perforation test, instrumented with a Hopkinson bar, and validated using experimental data from the literature. Moreover, the effects of quasi-static loading, landing rates, and boundary conditions on the perforation resistance of the studied graded core sandwich panels were discussed. The simulation results showed that the piercing force–displacement response of the graded core sandwich panels is affected by the core density gradient profiles. Besides, the energy absorption capability can be effectively enhanced by modifying the arrangement of the core layers with unclumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions.

Numerical investigation on the dynamic response of foam-filled corrugated core sandwich panels subjected to air blast loading

2017 ◽  
Vol 21 (3) ◽  
pp. 838-864 ◽  
Author(s):  
Yuansheng Cheng ◽  
Tianyu Zhou ◽  
Hao Wang ◽  
Yong Li ◽  
Jun Liu ◽  
...  
Keyword(s):  
Total Energy ◽  
Energy Absorption ◽  
Sandwich Panels ◽  
Blast Loading ◽  
Front Face ◽  
Back Side ◽  
Air Blast ◽  
Foam Filled ◽  
Blast Performance ◽  
Air Blast Loading

The ANSYS/Autodyn software was employed to investigate the dynamic responses of foam-filled corrugated core sandwich panels under air blast loading. The panels were assembled from metallic face sheets and corrugated webs, and PVC foam inserts with different filling strategies. To calibrate the proposed numerical model, the simulation results were compared with experimental data reported previously. The response of the panels was also compared with that of the empty (unfilled) sandwich panels. Numerical results show that the fluid–structure interaction effect was dominated by front face regardless of the foam fillers. Foam filling would reduce the level of deformation/failure of front face, but did not always decrease the one of back face. It is found that the blast performance in terms of the plastic deflections of the face sheets can be sorted as the following sequence: fully filled hybrid panel, front side filled hybrid panel, back side filled hybrid panel, and the empty sandwich panel. Investigation into energy absorption characteristic revealed that the front face and core web provided the most contribution on total energy absorption. A reverse order of panels was obtained when the maximization of total energy dissipation was used as the criteria of blast performance.

scholarly journals Dynamic Compressive Behaviors of Two-Layer Graded Aluminum Foams under Blast Loading

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1445 ◽  
Author(s):  
Minzu Liang ◽  
Xiangyu Li ◽  
Yuliang Lin ◽  
Kefan Zhang ◽  
Fangyun Lu
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Blast Resistance ◽  
Blast Loading ◽  
Deformation Energy ◽  
Aluminum Foams ◽  
Conflicting Objectives ◽  
Energy Dissipated ◽  
Transmitted Impulse ◽  
Energy Absorbing

Experimental and numerical analyses were carried out to reveal the behaviors of two-layer graded aluminum foam materials for their dynamic compaction under blast loading. Blast experiments were conducted to investigate the deformation and densification wave formation of two-layer graded foams with positive and negative gradients. The shape of the stress waveform changed during the propagation process, and the time of edge rising was extended. Finite element models of two-layer graded aluminum foam were developed using the periodic Voronoi technique. Numerical analysis was performed to simulate deformation, energy absorption, and transmitted impulse of the two-layer graded aluminum foams by the software ABAQUS/Explicit. The deformation patterns were presented to provide insights into the influences of the foam gradient on compaction wave mechanisms. Results showed that the densification wave occurred at the blast end and then gradually propagated to the distal end for the positive gradient; however, compaction waves simultaneously formed in both layers and propagated to the distal end in the same direction for the negative gradient. The energy absorption and impulse transfer were examined to capture the effect of the blast pressure and the material gradient. The greater the foam gradient, the more energy dissipated and the more impulse transmitted. The absorbed energy and transferred impulse are conflicting objectives for the blast resistance capability of aluminum foam materials with different gradient distributions. The results could help in understanding the performance and mechanisms of two-layer graded aluminum foam materials under blast loading and provide a guideline for effective design of energy-absorbing materials and structures.

A numerical study on the energy absorption of a bending-straightening energy absorber with large stroke

2018 ◽  
Vol 122 ◽  
pp. 30-41 ◽  
Author(s):  
Yao Yu ◽  
Guangjun Gao ◽  
Haipeng Dong ◽  
Weiyuan Guan ◽  
Jian Li
Keyword(s):  
Energy Absorption ◽  
Numerical Study ◽  
Energy Absorber

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.

Blast resistance and energy absorption of sandwich panels with layered gradient metallic foam cores

2017 ◽  
Vol 21 (2) ◽  
pp. 464-482 ◽  
Author(s):  
Lin Jing ◽  
Longmao Zhao
Keyword(s):  
Energy Absorption ◽  
Cross Sections ◽  
Blast Resistance ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Core Layer ◽  
Metallic Foam ◽  
Foam Core ◽  
Stress Distributions ◽  
Bottom Face

The dynamic response, blast resistance and energy absorption capability of clamped square sandwich panels comparing two aluminum alloy face-sheets and a layered gradient metallic foam core, subjected to air-blast loading, were studied numerically in this paper. Graded sandwich specimens with six different core-layer arrangements and three different face-sheet thickness arrangements were examined, respectively, compared to those ungraded sandwich panels with an equivalent nominally mass. Simulation results show that the blast resistance and energy absorption capability of sandwich panels with layered gradient metallic foam cores could be improved by optimizing the arrangements of different density metallic foam core-layers, and the graded sandwich panel with low-middle-high density core configuration has the best blast resistance capability. The blast resistance of graded sandwich panels with different thickness arrangements for top and bottom face-sheets has no obvious change tendency, since the normal stress distributions of their sandwich cross sections are controlled simultaneously by face-sheets and gradient foam core.

Experimental and numerical study of buckling behavior of foam-filled honeycomb core sandwich panels considering viscoelastic effects

2020 ◽  
pp. 109963622097516
Author(s):  
M Safarabadi ◽  
M Haghighi-Yazdi ◽  
MA Sorkhi ◽  
A Yousefi
Keyword(s):  
Energy Absorption ◽  
Viscoelastic Properties ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Face Sheet ◽  
Honeycomb Core ◽  
Buckling Behavior ◽  
Foam Filling ◽  
Foam Filled ◽  
Composite Face

Honeycomb sandwich panels are widely used in marine, aerospace, automotive and shipbuilding industries. High strength to weight and excellent energy absorption are features that make these structures unique. Foam filling the honeycomb core enhances the mechanical properties of sandwich panels considerably. In the present study, the buckling behavior of Nomex honeycomb core/glass-epoxy face sheet sandwich panel for both bare and foam-filled honeycomb core is investigated numerically and experimentally, considering the viscoelastic properties of the sandwich panel. Indeed, the viscoelastic properties of the composite face sheet and foam are determined by relaxation test and are implemented in ABAQUS using VUmat code. The finite element method is also performed using ABAQUS to model the buckling behavior of the sandwich panel incorporating both elastic and viscoelastic material behaviour. The effects of composite face sheet lay-up, core thickness, core cell size, and foam filling are also evaluated. The experimental and numerical results show that the foam increases the critical buckling load and energy absorption.

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