Numerical Investigation Into the Effect of Stand-Off Distance on the Blast Performance of Metallic Corrugated-Core Sandwich Panels

Author(s):  
Sipei Cai ◽  
Jun Liu ◽  
Yuansheng Cheng ◽  
Weiwei Hao ◽  
Pan Zhang

The ANSYS/AUTODYN software was employed to investigate the dynamic response of the metallic sandwich panels subjected to air blast loading. The sandwich panels were composed of two face sheets and a trapezoidal corrugated-core. To validate the numerical models, the simulation results were compared with experimental data reported previously. In the simulation works, the process of shock wave propagation and the structural dynamic response were analyzed. Meanwhile, the influences of the stand-off distance between the explosive charge and the front face sheet on the fluid-structure interaction effect, dynamic response and the energy absorption of sandwich panels were investigated. Numerical results demonstrated that the impulse intensity decreased dramatically with the increase of stand-off distance. The slapping between the front face sheet and the back face sheet could be observed at the stand-off distances of 50 mm and 100 mm, while the sandwich panel exhibited the “strong core” response mode under the stand-off distance of 150 mm. Investigations into energy absorption characteristic revealed that the total energy absorption reduced with the increase of stand-off distance. The front face and corrugated-core provided the most contribution on total energy absorption. Moreover, the energy absorption proportion of corrugated-core had a positive correlation with the stand-off distance.

2017 ◽  
Vol 21 (3) ◽  
pp. 838-864 ◽  
Author(s):  
Yuansheng Cheng ◽  
Tianyu Zhou ◽  
Hao Wang ◽  
Yong Li ◽  
Jun Liu ◽  
...  

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.


Author(s):  
Ting Liu ◽  
Yuansheng Cheng ◽  
Jun Liu ◽  
Ganchao Chen ◽  
Changhai Chen ◽  
...  

Abstract In this paper, the dynamic response of metallic Y-frame core sandwich plates subjected to air blast loading was investigated by employing the LS-DYNA software. The blast wave was generated by the directly detonation of TNT explosives. The deformation/failure modes and associated structural response were identified and analyzed in detail. Main attention was paid to explore the effects of face sheet thicknesses and core web thickness on the deformation response of Y-frame core sandwich plates. A comparison on the blast performance were drawn among the Y-frame core sandwich panel, corrugated core sandwich panel and solid plate in equal areal mass. Numerical results revealed that the Y-frame core sandwich panel experienced indent deformation in the front face, strut buckling in the core and large bending deformation in the back face under the stand-off distance of 100 mm. Increasing the face sheets and core web thicknesses could improve the blast performance of Y-frame core sandwich panels. The deflections of face sheets were sensitive to the variation of front face sheet and core thicknesses. Moreover, Y-frame sandwich panel has comparable anti-blast capacity with the corrugated counterparts and exhibits superior blast resistance than the solid plate.


Author(s):  
Changzai Zhang ◽  
Pan Zhang ◽  
Jun Liu ◽  
Jianqiang Pan ◽  
Yanjie Zhao ◽  
...  

Numerical investigations were conducted using the MSC.Dytran software on the dynamic response of functionally graded sandwich panels when subjected to underwater explosion. The effects of the number of layers and density distribution of graded cores on the blast performance were analyzed in several aspects under the constraint of equivalent mass. The simulation results have demonstrated that sandwich panels experience both bending and large plastic stretching deformation. Compared to single layered sandwich panel, those panels with graded cores overall possess smaller central permanent displacement and better energy absorption capability. Central deflection of bottom face sheet decreases as the density of cores descends from top to bottom face. A large proportion of the energy dissipates in the plastic deformation of top face sheet by the end of response, followed by the bottom face sheet, and core compression absorbers the minimum. Utilizing the high efficiency of energy absorption by adjusting those cores with greater density near to the top face sheet can further mitigate the damage from explosion.


Author(s):  
Shah Alam ◽  
Damodar Khanal

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.


2016 ◽  
Vol 20 (7) ◽  
pp. 861-884 ◽  
Author(s):  
QN Zhang ◽  
XW Zhang ◽  
GX Lu ◽  
D Ruan

To study the protection property of aluminum alloy sandwich panels with honeycomb cores under the attack of bullets or debris, quasi-static perforation, and ballistic impact tests were conducted, in which the thicknesses of the face sheet and core were 0.5–2.0 and 12.7 mm, respectively, while projectiles with diameter 7.5 mm and impact velocity 50–220 m/s were employed. Based on the experiments, the influences of impact velocity, face sheet thickness, core density as well as the nose shape of the projectiles were investigated. The results showed that in the impact tests, the sandwich panels dissipated much more energy than those in quasi-static perforation tests, and the energy absorption and ballistic limit of the sandwich panels increased with the increase of impact velocity. The influence of face sheet thickness was more remarkable than the core density, which was due to the relative density of honeycomb is too small. Although the increase of core density could induce the increase of energy absorption, this effect is more effective for thinner face sheet. Moreover, under the same impact velocity about 200 m/s and face sheet thickness 1.0 mm, the ballistic limit for conical-nosed projectile is highest, while it is lowest for flat-nosed projectile.


2020 ◽  
pp. 109963622097516
Author(s):  
M Safarabadi ◽  
M Haghighi-Yazdi ◽  
MA Sorkhi ◽  
A Yousefi

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.


2015 ◽  
Vol 82 (6) ◽  
Author(s):  
Murat Yazici ◽  
Jefferson Wright ◽  
Damien Bertin ◽  
Arun Shukla

The mechanisms by which different morphologies of preferentially foam filled corrugated panels deform under planar blast loading, transmit shock, and absorb energy are investigated experimentally and numerically for the purpose of mitigating back-face deflection (BFD). Six foam filling configurations were fabricated and subjected to shock wave loading generated by a shock tube. Shock tube experimental results obtained from high-speed photography were used to validate the numerical models. The validated numerical model was further used to analyze 24 different core configurations. The experimental and numerical results show that soft/hard arrangements (front to back) are the most effective for blast resistivity as determined by the smallest BFDs. The number of foam filled layers in each specimen affected the amount of front-face deflections (FFDs), but did relatively little to alter BFDs, and results do not support alternating foam filling layers as a valid method to attenuate shock impact.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Pan Zhang ◽  
Yuansheng Cheng ◽  
Jun Liu

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.


2021 ◽  
pp. 109963622199387
Author(s):  
Subramani Anbazhagan ◽  
Periyasamy Manikandan ◽  
Gin B Chai ◽  
Sunil C Joshi

The load response, energy absorption, different damage mechanisms and failure modes of sandwich panels subjected to complete perforation by quasi-static indentation and the insights gleaned are presented in this paper. The experimental campaign was carried out on samples made of different type of facesheets: Aluminium, glass fibre-reinforced plastic and metal-composite hybrid (combined aluminium and GFRP) with two different core heights. Reliable numerical models were developed with appropriate constitutive material and damage model for facesheets and honeycomb core to complement the experimental observations. Good agreement between experimental results and numerical predictions in terms of force-displacement response and perforation damage ensure the fidelity of the developed numerical model. Effects of facesheet type, core height, energy absorbed by the constituent layers, damage evolution history are briefly discussed. It was observed that the energy absorption of sandwich panels and peak indentation force resisted by the top and bottom facesheet are strongly dependent on its metal-volume fraction, whilst unaffected with the height of the core. Recommendations for developing computationally efficient numerical models were provided.


2018 ◽  
Vol 22 (7) ◽  
pp. 2139-2156 ◽  
Author(s):  
Lihong Yang ◽  
Xiao Han ◽  
Lijia Feng ◽  
Zongbing Chen ◽  
Guocai Yu ◽  
...  

This research focuses on the dynamic response of sandwich panels with multilayered graded hourglass lattice core subjected to blast loading. A three-layer lattice core configuration is proposed to improve the absorption efficient of kinetic energy resulted from blast shock wave. The relative density of each core layer is changed with sectional dimension of core truss members to regulate the energy absorption of each core layer. Three-dimensional numerical simulation analyses of dynamic response are carried out, and the applied impulsive pressure distribution on the surface of the panels is calculated using the CONWEP code. The panels are made of stainless steel AL6XN, which is assumed to follow bilinear strain hardening and strain rate-dependence. Peak back sheet deflection and energy absorption of core layers for four types of hourglass lattice panels are comparatively analyzed and the effects of load intensity on the peak deflection are discussed. Furthermore, the near-optimal configuration under blast loadings is proposed.


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