STRUCTURAL RESPONSE OF ALUMINIUM FOAM HYBRID SANDWICH PANELS UNDER THREE-POINT BENDING LOADING

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1733-1738 ◽  
Author(s):  
KAVEH R. KABIR ◽  
TANIA VODENITCHAROVA ◽  
MARK HOFFMAN
Keyword(s):  
Failure Modes ◽  
Bending Strength ◽  
Sandwich Panels ◽  
Structural Response ◽  
Foam Core ◽  
Three Point Bending ◽  
Closed Cell ◽  
Core Thickness ◽  
Bending Loading ◽  
Foam Thickness

The present study focuses on the structural response of sandwich panels consisting of a commercial closed-cell foam core and thin aluminium sheet skins under static three-point bending loading. Panels of different thicknesses and span lengths were tested, and the influence of the foam density, core thickness and skin type on the response was revealed. The failure modes in bending were greatly dependent on the span length but independent on the foam thickness. For short spans, the deformed shape at failure was asymmetric, as opposed to a symmetric mode for long spans. The density and thickness of the foam core, the presence of reinforcing face sheets and the beam span determined the failure load and bending strength of the sandwich panels.

scholarly journals Three-Point Bending Response of Corrugated Core Metallic Sandwich Panels Having Different Core Configurations – An Experimental Study

2019 ◽  
Vol 9 (2) ◽  
pp. 3981-3984
Author(s):  
E. Zurnaci ◽  
H. Gokkaya ◽  
M. Nalbant ◽  
G. Sur
Keyword(s):  
Sandwich Panel ◽  
Failure Modes ◽  
Experimental Testing ◽  
Sandwich Panels ◽  
Bending Tests ◽  
Bending Performance ◽  
Three Point Bending ◽  
Aluminum Sheets ◽  
Bending Loading ◽  
Bending Response

Bending response of corrugated core metallic sandwich panels was studied experimentally under three-point bending loading. Two different core configurations were used: the corrugated monolithic core and the corrugated sliced core. The trapezoidal corrugated cores were manufactured from aluminum sheets via a sheet metal bending mould. After the sandwich panel samples were prepared, they were subjected to three-point bending tests. The load and displacement responses of the sandwich panels having different core configurations were obtained from the experimental testing. The influence of the core configuration on the three-point bending response and failure modes was then investigated. The experimental results revealed that the corrugated sliced core configuration exhibited an improved bending performance compared to the corrugated monolithic core configuration.

scholarly journals Mechanical performance of marine sandwich composites subjected to flatwise compression and flexural loading: Effect of resin pins

2018 ◽  
Vol 22 (6) ◽  
pp. 2030-2048 ◽  
Author(s):  
F Balıkoğlu ◽  
TK Demircioğlu ◽  
M Yıldız ◽  
N Arslan ◽  
A Ataş
Keyword(s):  
Vinyl Ester ◽  
Failure Load ◽  
Mechanical Performance ◽  
Sandwich Panels ◽  
Foam Core ◽  
Compression Stress ◽  
Three Point Bending ◽  
Poly Vinyl Chloride ◽  
Circular Holes ◽  
Core Thickness

Mechanical performance of marine sandwich panels comprising E-glass/vinyl ester face sheets and perforated poly-vinyl chloride foam core was evaluated and compared with conventional foam core sandwich panels. Circular holes through the foam core thickness were drilled with 12 different arrangements in square patterns and the holes were filled with the resin during the infusion process which created the through-the-thickness solid resin pins. The effect of each pattern on the flatwise compression and core shear properties of the sandwich panels were experimentally investigated. The three-point bending maximum failure load of perforated foam core sandwich panels was increased over 133.8% by increasing the diameter of the resin pins at the expense of increased panel weight up to 67%. The flatwise compression stress to induce core crushing was significantly increased by reinforcing the resin pins.

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.

scholarly journals An Investigation on Mechanical Behavior of Tooth-Plate-Glass-Fiber Hybrid Sandwich Beams

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Honglei Xie ◽  
Li Wan ◽  
Bo Wang ◽  
Haiping Pei ◽  
Weiqing Liu ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Failure Modes ◽  
Bending Strength ◽  
Fibrous Composite ◽  
Strain Energy Release ◽  
Metal Plate ◽  
Plate Glass ◽  
Foam Core ◽  
Sandwich Beams ◽  
Tooth Plate

Tooth-plate-glass-fiber hybrid sandwich (TFS) is a type of sandwich composites fabricated by vacuum-assisted resin infusion process, in which glass fiber facesheets reinforced by metal plate are connected to foam core through tooth nails. Bending properties and interlaminar properties of TFS beams with various foam densities were investigated by flexural tests and DCB (double cantilever beam) tests. The test results showed that by increasing the foam core density from 35 kg/m3 to 150 kg/m3, the peak strength of TFS beams significantly increased by 168% to 258% compared with similar sandwich beams with fibrous composite facesheets. With the change of foam density and span length, the main failure modes are core shear and facesheet indentation beneath the loading roller. The interlaminar strain energy release rates of TFS specimens also increased by increasing the density of the foam. In addition, an analytical model was used to predict the ultimate bending strength of TFS beams, which were in good accordance with the experimental results.

Bending Properties and Failure Mechanisms of Tapered 3D Braided Composites

2011 ◽  
Vol 332-334 ◽  
pp. 1468-1471 ◽  
Author(s):  
Can Can Cheng ◽  
Zhao Lin Liu ◽  
Li Fang Liu ◽  
Jian Yong Yu
Keyword(s):  
Failure Modes ◽  
Bending Strength ◽  
Failure Mechanisms ◽  
Reduction Technique ◽  
Braided Composites ◽  
Bending Properties ◽  
Bending Tests ◽  
Three Point Bending ◽  
Bending Modulus ◽  
3D Braided Composites

Tapered 3D braided composites are prepared by column yarn-reduction technique, unit yarn-reduction technique and cutting, respectively. Bending properties in the tapered regions of the composites are obtained by three-point bending tests, and SEM photographs of the fracture surfaces are observed to analyze the failure mechanisms. Results show that bending modulus and bending strength of the yarn-reduction composites are significantly higher than those of the cut composites, and the unit yarn-reduction composites are slightly stronger than the column yarn-reduction composites. The saw-tooth propagation of matrix crackings and interfacial debondings are the primary failure mechanisms of the yarn-reduction composites, while yarn breakages and yarn pulling-outs are the main failure modes of the cut composites.

Thickness Effect of Polyurethane Foam Core on the Flexural Behaviour of Composite Sandwich Materials

2015 ◽  
Vol 758 ◽  
pp. 1-6
Author(s):  
Pramaditya Ardiyanto ◽  
Putu Suwarta ◽  
Sutikno ◽  
Indra Sidharta ◽  
Wahyu Wijanarko
Keyword(s):  
Failure Mechanism ◽  
Polyurethane Foam ◽  
Bending Strength ◽  
Thickness Effect ◽  
Positive Trend ◽  
Foam Core ◽  
High Modulus ◽  
Composite Sandwich ◽  
Material Stiffness ◽  
Core Thickness

This study explored the feasibility of flexural performance of composite sandwich material composed of various low density polyurethane foam core thickness sandwiched between GFRP skins. The mechanical behaviour of this material was assessed by carrying out a flexural testing. Each spesimen had a nominal dimensions of 110 mm x 30 mm x (c + 4 mm). These spesimens with various core thickness (c) of 2 mm. 5 mm. and 8 mm were then tested in three point bending according to ASTM C 393-00. This study revealed that. by incorporating the thickest core ( 8 mm ) . the bending strength decreases by 42.3 % compared to 5 mm core and it further decreases by 72.6 % compared to 2 mm core. The material stiffness showed positive trend for the thickest core (8 mm). it increases by 53.1 % and 78.1 % compared to 5 mm core and 2 mm core respectively. Low shear modulus of polyurethane foam core contributed to the low bending strength of composite sandwich material with 8 mm core. This was further confirmed by failure analysis under optical microscope which revealed that core shear failure was the dominant failure mechanism for 8 mm core. Meanwhile the dominant failure mechanism for 2 mm core and 5 mm core was microbuckling which confirm the high modulus of GFRP skin. The material stiffness was affected by the high modulus of GFRP skin and the core thickness.

Design of Hybrid Sandwich Panel with Aluminum Foam Core and Carbon Fiber Reinforced Plastic Face Sheets under Three-Point Bending

2006 ◽  
Vol 111 ◽  
pp. 63-66 ◽  
Author(s):  
K. Mohan ◽  
Tick Hon Yip ◽  
Idapalapati Sridhar ◽  
H.P. Seow
Keyword(s):  
Carbon Fiber ◽  
Aluminum Foam ◽  
Failure Modes ◽  
Shear Failure ◽  
Elastic Stiffness ◽  
Foam Core ◽  
Fiber Reinforced ◽  
Three Point Bending ◽  
Structural Applications ◽  
Carbon Fiber Reinforced

Aluminum foams are very popular material for structural applications because of its attractive combination of properties. Structural performance of those foams can be enhanced by bonding them between strong and stiff face sheets such as carbon fiber reinforced plastics (CFRP). The response of hybrid sandwich panels comprising aluminum foam core and CFRP face sheets were investigated under three-point bending and measured response is verified with finite element numerical simulations. Core indentation and core shear, failure modes are identified. Experimentally measured elastic stiffness and failure load of thee tested beams were found to be in good agreement with the numerical simulation and analytical predictions.

Failure Modes of Sandwich Structures

2007 ◽  
Vol 7-8 ◽  
pp. 23-28 ◽  
Author(s):  
E.E. Gdoutos
Keyword(s):  
Failure Modes ◽  
Failure Mechanisms ◽  
Core Material ◽  
Cantilever Beams ◽  
Compressive Failure ◽  
Three Point Bending ◽  
Composite Sandwich ◽  
Closed Cell ◽  
Ultimate Failure ◽  
Cell Foam

A thorough investigation of the failure mechanisms of composite sandwich beams under four- and three-point bending and cantilever beams was undertaken. The beams were made of unidirectional carbon/epoxy (AS4/3501-6) facings and a PVC closed-cell foam (Divinycell) core. Two types of core material H100 and H250 with densities 100 and 250 kg/m3, respectively, were used. The failure modes investigated are face sheet compressive failure, core failure and facing wrinkling. The various modes have been studied separately and both initiation and ultimate failure have been determined. Initiation of a particular failure mode and triggering and interaction with other failure modes was also investigated.

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