The effect of foam core density at various slenderness ratios on axial strength of sandwich panels with glass-FRP skins

2016 ◽  
Vol 106 ◽  
pp. 129-138 ◽  
Author(s):  
Luke CoDyre ◽  
Amir Fam
Keyword(s):  
Sandwich Panels ◽  
Foam Core ◽  
Core Density ◽  
Axial Strength ◽  
Glass Frp

Flexural and axial behaviour of sandwich panels with bio-based flax fibre-reinforced polymer skins and various foam core densities

2016 ◽  
Vol 20 (5) ◽  
pp. 595-616 ◽  
Author(s):  
Luke CoDyre ◽  
Kenneth Mak ◽  
Amir Fam
Keyword(s):  
Sandwich Panels ◽  
Single Layer ◽  
Flax Fibre ◽  
Foam Core ◽  
Core Density ◽  
Axial Capacity ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Stub Column ◽  
Glass Frp

This study investigates the effect of foam core density on the behaviour of sandwich panels with novel bio-composite unidirectional flax fibre-reinforced polymer skins, along with a comparison to panels of conventional glass-FRP skins. Eighteen 1000 mm long flexural specimens and 18 500 mm long stub column specimens were fabricated and tested. All specimens had a foam core of 100 × 50 mm2 cross-section with symmetrical 100 mm wide skins. The study compares the effect of three separate polyisocyanurate foam cores when used in conjunction with either three layers of flax fibre-reinforced polymer or a single glass-FRP layer for each skin. Flexural specimens were tested in four-point bending and stub columns were tested under axial compression with pin–pin end conditions. Doubling the core density from 32 to 64 kg/m3 and tripling the density to 96 kg/m3 led to flexural strength increases of 82 and 213%, respectively, for flax fibre-reinforced polymer skinned panels, and comparable increases in glass-FRP skinned panels. Similarly, flax fibre-reinforced polymer-skinned columns showed similar increases in ultimate axial capacity of 85% and 196%, while glass-FRP- skinned columns experienced lower increases when core density was varied. The three-layered flax fibre-reinforced polymer skin, only 17% thicker than the single layer glass-FRP skin, was shown to provide equivalent flexural and axial strengths at all three core densities, within −5 to +13%.

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.

Closure to “Local Failure of Plastic-Foam Core Sandwich Panels”

1970 ◽  
Vol 96 (8) ◽  
pp. 1803-1805
Author(s):  
Billy J. Harris ◽  
Gene M. Nordby
Keyword(s):  
Sandwich Panels ◽  
Local Failure ◽  
Foam Core ◽  
Plastic Foam

Local Failure of Plastic-Foam Core Sandwich Panels

1969 ◽  
Vol 95 (4) ◽  
pp. 585-610
Author(s):  
Billy J. Harris ◽  
Gene M. Nordby
Keyword(s):  
Sandwich Panels ◽  
Local Failure ◽  
Foam Core ◽  
Plastic Foam

scholarly journals Thermal-mechanical behavior of sandwich panels with closed-cell foam core under intensive laser irradiation

2014 ◽  
Vol 18 (5) ◽  
pp. 1607-1611 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Wei-Dong Song ◽  
Hui-Ping Tang ◽  
Zhi-Hua Wang ◽  
Long-Mao Zhao
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stress ◽  
Specific Heat ◽  
Laser Irradiation ◽  
Thermal Deformation ◽  
Sandwich Panels ◽  
Protective Layer ◽  
Foam Core ◽  
Closed Cell ◽  
Analysis Models

Temperature field and thermal deformation of sandwich panels with closed-cell aluminum alloy foam core and heat-protective layer, which are subjected to Gaussian laser beam intensively irradiating, are investigated numerically. In transient heat analysis models, the influence of thermal conductivity, specific heat, and thickness of heat-protective layer on the temperature rise of the sandwich panels is calculated. In stress analysis models, a sequence coupled numerical method is utilized to simulate the thermal stress and deformation of sandwich panels induced by thermal expansion. Simulation results indicate that the temperature at center of sandwich panel increases firstly and then drops gradually with the increase of thermal conductivity of heat-protective layer after laser irradiation, and the critical thermal conductivity is obtained, while it decreases with the increase of specific heat and thickness of heat-protective layer. The thermal stress verifies the ?Cyclo-hoop effect?, i. e. radial stress is compression stress in ?hot zone? and tension stress in ?cold zone?. The max thermal deformation of sandwich panels slightly increases with the increase of thickness of heat-protective layer for given specific heat and thermal conductivity.

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