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.

Shape Memory Polymer With Aluminum Tube Reinforced Impact Resistant Sandwich Core

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

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 sandwich core is proposed which is a hybrid core consisting of hollow metallic millitubes reinforced Shape Memory Polymer matrix. The objective of this study was to characterize its dynamic performances. The core consisted of programmed shape memory polymer resin. Low velocity (4m/s) impact tests demonstrated that new core panel may be considered a promising option for critical structural applications featured by debonding and multiple impact tolerance.

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.

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 The low-velocity impact and compression after impact (CAI) behavior of foam core sandwich panels with shape memory alloy hybrid face-sheets

2019 ◽  
Vol 26 (1) ◽  
pp. 517-530 ◽  
Author(s):  
Ye Wu ◽  
Yun Wan
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Sandwich Panels ◽  
Image Correlation ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Velocity Impact ◽  
Compression After Impact ◽  
The Impact

AbstractDue to the properties of shape memory effect and super-elasticity, shape memory alloy (SMA) is added into glass fiber reinforced polymer (GFRP) face-sheets of foam core sandwich panels to improve the impact resistence performance by many researchers. This paper tries to discuss the failure mechanism of sandwich panels with GF/ epoxy face-sheets embedded with SMA wires and conventional 304 SS wire nets under low-velocity impact and compression after impact (CAI) tests. The histories of contact force, absorbed energy and deflection during the impact process are obtained by experiment. Besides, the failure modes of sandwich panels with different ply modes are compared by visual inspection and scanning electron microscopy (SEM). CAI tests are conducted with the help of digital image correlation (DIC) technology. Based on the results, the sandwich panels embedded with SMA wires can absorb more impact energy, and show relatively excellent CAI performance. This is because the SMA wires can absorb and transmit the energy to the outer region of GFRP face-sheet due to the super-elasticity-behavior. The failure process and mechanism of the CAI test is also discussed.

Study on the Residual Compressive Strength of a Composite Sandwich Panel with Foam Core after Low Velocity Impact

2012 ◽  
Vol 430-432 ◽  
pp. 484-487 ◽  
Author(s):  
Zong Hong Xie ◽  
Jiang Tian ◽  
Jian Zhao ◽  
Wei Li
Keyword(s):  
Compressive Strength ◽  
Failure Criterion ◽  
Sandwich Panel ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Velocity Impact ◽  
Residual Compressive Strength ◽  
Composite Sandwich ◽  
The Impact

The residual compressive strength of a foam core sandwich panel after low-velocity impact was studied by using experimental and analytical methods. The test specimens were compressed uniaxially after they were subjected to a low-velocity-impact. From the observation in the test, one can conclude that the subsequent core crushing around the impact region is the major failure mode in the sandwich structure. A failure criterion named Damage Propagation Criterion was proposed to predict the residual compressive load bearing capability of the low-velocity impacted composite sandwich panel. The characteristic value used in this failure criterion can be calculated by an analytical model developed or by conducting the Sandwich Compression after Impact test.

On low-velocity impact response of foam-core sandwich panels

2020 ◽  
Vol 181 ◽  
pp. 105681 ◽  
Author(s):  
Xintao Huo ◽  
Hao Liu ◽  
Quantian Luo ◽  
Guangyong Sun ◽  
Qing Li
Keyword(s):  
Sandwich Panels ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Velocity Impact

scholarly journals An Investigation on Low Velocity Impact Response of Multilayer Sandwich Composite Structures

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
S. Jedari Salami ◽  
M. Sadighi ◽  
M. Shakeri ◽  
M. Moeinfar
Keyword(s):  
Composite Structures ◽  
Sandwich Panel ◽  
Testing Machine ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Core Material ◽  
Sandwich Composite ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Core

The effects of adding an extra layer within a sandwich panel and two different core types in top and bottom cores on low velocity impact loadings are studied experimentally in this paper. The panel includes polymer composite laminated sheets for faces and the internal laminated sheet called extra layer sheet, and two types of crushable foams are selected as the core material. Low velocity impact tests were carried out by drop hammer testing machine to the clamped multilayer sandwich panels with expanded polypropylene (EPP) and polyurethane rigid (PUR) in the top and bottom cores. Local displacement of the top core, contact force and deflection of the sandwich panel were obtained for different locations of the internal sheet; meanwhile the EPP and PUR were used in the top and bottom cores alternatively. It was found that the core material type has made significant role in improving the sandwich panel’s behavior compared with the effect of extra layer location.

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