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.

Impact/Debonding Tolerant Sandwich Panel With Aluminum Tube Reinforced Foam Core

2011 ◽  
Author(s):  
Gefu Ji ◽  
Zhenyu Ouyang ◽  
Guoqiang Li ◽  
Su-Seng Pang
Keyword(s):  
Sandwich Panel ◽  
Load Capacity ◽  
Sandwich Panels ◽  
Interface Debonding ◽  
Type I ◽  
Foam Core ◽  
Type Ii ◽  
Polymer Resin ◽  
The Core ◽  
Structural Applications

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new foam core is proposed which is a hybrid core consisting of hollow metallic microtubes reinforced polymer matrix. The objective of this study was to characterize its static and dynamic performances. Two types of new hybrid cores were investigated in this work. One consisted of polymer resin reinforced by transversely aligned continuous metallic militubes, denoted as type-I sandwich panel. The other was made of polymer resin reinforced by aligned continuous in-plane metallic militubes, denoted as type-II sandwich panel. Additionally, the traditional sandwich panels with polymeric syntactic foam core were also prepared for comparisons. Static and impact tests demonstrated that interface debonding and subsequent shear failure in the core could be largely excluded from the type-II panel. Meanwhile, a significant transition to ductile failure was observed in type-II sandwich panel with dramatically enhanced load capacity and impact energy dissipation. The results indicated that type-II panel may be considered a promising option for critical structural applications featured by debonding and impact tolerance.

Novel Impact/Debonding Tolerant Sandwich Panel With Millitubes Grid Stiffened Foam Core

2012 ◽  
Author(s):  
Guoqiang Li ◽  
Gefu Ji ◽  
Su-Seng Pang
Keyword(s):  
Sandwich Panel ◽  
Structural Integrity ◽  
Safety Concern ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
The Core ◽  
Sandwich Construction ◽  
Structural Applications

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new foam core is proposed which is a hybrid core consisting of grid stiffened hollow metallic millitubes reinforced polymer matrix. The objective of this study was to characterize its dynamic performances. The core consisted of polymer resin reinforced by grid stiffened continuous metallic millitubes. Low velocity impact test demonstrated that new core panel may be considered a promising option for critical structural applications featured by debonding and multiple impact tolerance.

Dynamic pulse buckling and failure analysis of the single curved composite sandwich panel using the core high-order theory

2020 ◽  
Vol 234 (10) ◽  
pp. 1990-2011
Author(s):  
Seyed Ali Ahmadi ◽  
Mohammad Hadi Pashaei ◽  
Ramazan-Ali Jafari-Talookolaei
Keyword(s):  
Sandwich Panel ◽  
Failure Modes ◽  
Viscoelastic Model ◽  
Sandwich Panels ◽  
High Order ◽  
Foam Core ◽  
Composite Sandwich ◽  
The Core ◽  
Pulse Buckling ◽  
Dynamic Pulse

The current study aims to investigate the facesheet dynamic pulse buckling of simply supported, cylindrical composite sandwich panels using the Budiansky–Roth buckling criterion. The foam core has been modeled with isotropic elastic-perfectly plastic properties and various failure modes of the sandwich panel like facesheet fracture, foam shear fracture, and foam yield are investigated. The extended high-order sandwich panel core theory was used to model the compressibility of the core. To study the mechanical properties of the viscoelastic foam core, the Kelvin–Voigt linear viscoelastic model was applied. The transient responses and stress components obtained from the present method are compared with finite element solutions using commercial software ANSYS and those reported in the literature. Accordingly, reasonable agreement is observed. It was shown that the pulse local buckling strength of the panel increases with a decrease in the panel radius or an increase in the thickness of the panel, and facesheet fracture is considered more a likely failure mode of these sandwich panels.

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.

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.

Shear-Lag Effect in Sandwich Panels With Stiffeners Under Three-Point Bending

1980 ◽  
Vol 47 (2) ◽  
pp. 383-388 ◽  
Author(s):  
K. Kemmochi ◽  
T. Akasaka ◽  
R. Hayashi ◽  
K. Ishiwata
Keyword(s):  
Strain Distribution ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Bending Rigidity ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Three Point Bending ◽  
The Core ◽  
Lag Effect ◽  
Modified Theory

In this paper, a modified theory based upon Reissner’s procedure for the shear-lag effect of the sandwich panel is presented, which includes the effects of the anisotropy of the faces and the shearing rigidity of the core. In order to verify this theory, bending experiments were performed with sandwich panels composed of a soft core, stiffeners, and orthotropic faces. It was found that the effective bending rigidity calculated from this theory was lower than that derived from the classical bending theory and that the theoretical strain distribution on the faces agreed well with the experimental results.

Dynamic Response of Metallic Y-Frame Core Sandwich Panels Subjected to Air Blast Loading: Numerical Investigation

2019 ◽  
Author(s):  
Ting Liu ◽  
Yuansheng Cheng ◽  
Jun Liu ◽  
Ganchao Chen ◽  
Changhai Chen ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Face Sheet ◽  
Front Face ◽  
Sandwich Plates ◽  
Air Blast ◽  
Solid Plate ◽  
Blast Performance ◽  
Air Blast Loading

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.

Experimental investigation on the performance of PVC foam core sandwich panels subjected to contact underwater explosion

2020 ◽  
Vol 235 ◽  
pp. 111796 ◽  
Author(s):  
Tianyu Zhou ◽  
Yuansheng Cheng ◽  
Yanjie Zhao ◽  
Lunping Zhang ◽  
Haikun Wang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Sandwich Panels ◽  
Underwater Explosion ◽  
Foam Core

scholarly journals Impact perforation of sandwich panels with graded hollow sphere cores: Numerical and Analytical investigations

2021 ◽  
Vol 250 ◽  
pp. 02027
Author(s):  
Ibrahim Elnasri
Keyword(s):  
Boundary Conditions ◽  
Hollow Sphere ◽  
Sandwich Panel ◽  
Peak Load ◽  
Sandwich Panels ◽  
Core Density ◽  
Plateau Stress ◽  
The Core ◽  
The Impact ◽  
Force Displacement

In this study, we numerically and analytically 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 effect of boundary conditions on the perforation resistance of the studied graded core sandwich panels was 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 un-clumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions. Finally, an analytical model, taken account only gradient in the quasi-static plateau stress, is developed to predict the top skin pic peak load of the graded sandwich panel.

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