scholarly journals Three-Point Bending Fatigue Behavior of Aluminum Foam Sandwich Panels with Different Density Core Material

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1542
Author(s):  
Cheng Yao ◽  
Zhengfei Hu ◽  
Fan Mo
Keyword(s):  
Aluminum Foam ◽  
Failure Modes ◽  
Fatigue Behavior ◽  
Sandwich Panels ◽  
High Density ◽  
Core Material ◽  
Adhesively Bonded ◽  
Bending Tests ◽  
Three Point Bending ◽  
Lower Porosity

The monotonic and fatigue strength of adhesively bonded aluminum foam sandwich panels with different densities of core aluminum foam (0.3 g/cm3, 0.4 g/cm3, 0.6 g/cm3) were investigated in three-point bending tests to study the flexural fatigue behavior of aluminum foam sandwich panels. The force cycle curves, deflection curves, and hysteretic curves are presented to describe the fatigue process of aluminum foam sandwich panels. Their fatigue fracture modes are completely different, the failure modes of the low-density cores (0.3 g/cm3, 0.4 g/cm3) are debonding and face fatigue, whereas the failure mode of the high-density core (0.6 g/cm3) is face fatigue without debonding. The reason is that high-density aluminum foam cores with lower porosity have a larger joining face, which can also provide higher strength and lead to a longer fatigue life.

Failure mode maps for four-point-bending of hybrid sandwich structures with carbon fiber reinforced plastic face sheets and aluminum foam cores manufactured by a polyurethane spraying process

2017 ◽  
Vol 21 (8) ◽  
pp. 2654-2679 ◽  
Author(s):  
Peter Rupp ◽  
Peter Elsner ◽  
Kay A Weidenmann
Keyword(s):  
Carbon Fiber ◽  
Failure Mode ◽  
Aluminum Foam ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Bending Tests ◽  
The Core ◽  
Four Point Bending ◽  
The Face ◽  
Spraying Process

This work focuses on failure mode maps of sandwich panels exposed to bending load, which were produced using a polyurethane spraying process. This process allows for an automated production of sandwich panels omitting a separate bonding step of the face sheets to the core. The investigated sandwich panels consisted of carbon fiber reinforced face sheets in various configurations, and four different core structures of aluminum foam or Nomex honeycomb. After production, measurements of the pores inside the core foam structures, the fiber package thickness inside the face sheets, and the density homogeneity of the core structure were made using X-ray computed tomography. The failure mode maps were based on the individual mechanical properties of the face sheets and the core, determined by mechanical testing. The critical forces determining the failure modes were partially modified to fit the application on foam core structures and face sheets with a porous matrix. The verification of the failure modes was performed with four-point bending tests. Since all tested configurations of sandwich specimens were produced using the same process route, the applied models for the creation of the failure mode maps could be verified for numerous parameter combinations. Except for two parameters with inconstant properties, the failure modes determined by the failure mode maps matched the observed failure modes determined by the bending tests.

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.

Fatigue Behavior of Composite Sandwich Panels Under Three Point Bending Load

2020 ◽  
Vol 91 ◽  
pp. 106795
Author(s):  
Mingze Ma ◽  
Weixing Yao ◽  
Wen Jiang ◽  
Wei Jin ◽  
Yan Chen ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Sandwich Panels ◽  
Three Point Bending ◽  
Composite Sandwich Panels ◽  
Composite Sandwich ◽  
Bending Load

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.

scholarly journals Core failure in sandwich structures subjected to water slamming loads

2019 ◽  
Vol 21 (5) ◽  
pp. 1751-1772
Author(s):  
MA Battley ◽  
TD Allen
Keyword(s):  
Transverse Shear ◽  
High Speed ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Core Material ◽  
Polymeric Foams ◽  
Failure Mechanics ◽  
The Core ◽  
High Elongation ◽  
Core Materials

Sandwich composite materials are widely used within the marine industry, particularly as hull panels. Water impact loads, known as slamming, can be very significant for these structures, particularly for high-speed craft. These loadings generate local regions of high transverse shear forces near panel boundaries, which can result in transverse shear failures of core materials. The transient nature of slamming loads can cause stress rates that are high enough to affect the strength of the core material, particularly for polymeric foams. Despite the significant body of work on the constitutive behaviour and failure mechanics of sandwich core materials, there is a lack of understanding of how core materials fail in transverse shear during slamming events. There is also only very limited knowledge of how the core shear strengths measured using standardised, often quasi-static material coupon testing relate to their behaviour in a panel-slamming situation. This paper contributes in two novel areas; controlled experimental characterisation of the failure mechanics of sandwich panels subjected to water slamming to understand and quantify the strength of different polymeric core materials, comparison of the failure modes and transverse shear strength of slam-loaded sandwich panels to predictions from material coupon properties. Core types include low, medium and high elongation polymeric foams. The results demonstrate that the more ductile foams perform better as panel structures under slamming relative to their quasi-static properties compared with the more brittle cores. Prediction of the strength of a panel is shown to be highly dependent on the load distribution and whether the static or dynamic core strength is considered. The results support empirical experience that ductile foams perform well under slamming loads, and that high-elongation materials can perform better in slamming situations than predicted by their quasi-static strengths.

Experimental and numerical investigation on bending and compressive behavior of carbon-epoxy sandwich panel with novel M-shaped core

2022 ◽  
pp. 089270572110466
Author(s):  
Himan Khaledi ◽  
Yasser Rostamiyan
Keyword(s):  
Polyurethane Foam ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Bending Tests ◽  
Three Point Bending ◽  
Composite Sandwich ◽  
Compressive Loads ◽  
Lattice Core ◽  
Force Displacement ◽  
Good Agreement

Present paper has experimentally and numerically investigated the mechanical behavior of composite sandwich panel with novel M-shaped lattice core subjected to three-point bending and compressive loads. For this purpose, a composite sandwich panel with M-shaped core made of carbon fiber has been fabricated in this experiment. In order to fabricate the sandwich panels, the vacuum assisted resin transfer molding (VARTM) has been used to achieve a laminate without any fault. Afterward, polyurethane foam with density of 80 kg/m3 has been injected into the core of the sandwich panel. Then, a unique design was presented to sandwich panel cores. The study of force-displacement curves obtained from sandwich panel compression and three-point bending tests, showed that an optimum mechanical strength with a considerable lightweight. It should be noted that the experimental data was compared to numerical simulation in ABAQUS software. According to the results, polyurethane foam has improved the flexural strength of sandwich panels by 14% while this improvement for compressive strength is equal to 23%. As well as, it turned out that numerical results are in good agreement with experimental ones and make it possible to use simulation instead of time-consuming experimental procedures for design and analysis.

An investigation on the effect of nanoparticle reinforcement and weld surface shape on bending behavior of rotary friction-welded high-density polyethylene

2021 ◽  
pp. 146442072110441
Author(s):  
Vahid Asghari ◽  
Abdolvahed Kami ◽  
Abbasali Bagheri
Keyword(s):  
High Density Polyethylene ◽  
Joint Strength ◽  
Bending Strength ◽  
Welded Joint ◽  
High Density ◽  
Surface Shape ◽  
Bending Tests ◽  
Three Point Bending ◽  
Rotary Friction Welding ◽  
Bending Behavior

In this research, high-density polyethylene rods were joined together using rotary friction-welding. The effects of nanoparticle reinforcement and weld surface shape on the welded joint strength were investigated. To this aim, high-density polyethylene rods with a length of 50 mm and a diameter of 22 mm were machined, and three weld surface shapes, that is, flat, step, and conic shapes (on male and female counterparts), were created. The high-density polyethylene rods were rotary friction-welded with the addition of ZnO and SiO2 nanoparticles. The bending strength of rotary friction-welded rods was assessed by conduction of three-point bending tests. The results showed that both the weld surface shape and nanoparticles influence the bending strength of the welded joints. It was found that the step sample welds have higher bending strength (average bending depth and force of 6.27 mm and 2027.8 N, respectively). Furthermore, except for the case of flat samples, the addition of the reinforcement nanoparticles resulted in the improvement of the bending strength of the rotary friction-welded rods.

scholarly journals Fabrication and Fatigue Behavior of Aluminum Foam Sandwich Panel via Liquid Diffusion Welding Method

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 582 ◽  
Author(s):  
Cheng Yao ◽  
Zhengfei Hu ◽  
Fan Mo ◽  
Yu Wang
Keyword(s):  
Failure Mode ◽  
Aluminum Foam ◽  
Fatigue Behavior ◽  
Sandwich Panels ◽  
Transitional Zone ◽  
Peel Strength ◽  
Diffusion Welding ◽  
Chemical Compositions ◽  
Liquid Diffusion ◽  
Joining Strength

Aluminum Foam Sandwich panels were fabricated via liquid diffusion welding and glue adhesive methods. The Microstructure of the Aluminum Foam Sandwich joints were analyzed by Optical Microscopy, Scanning Electron Microscopy, and Energy Dispersive Spectroscopy. The metallurgical joints of Aluminum Foam Sandwich panels are compact, uniform and the chemical compositions in the diffusion transitional zone are continuous, so well metallurgy bonding between Aluminum face sheet and foam core was obtained. The joining strength of an Aluminum Foam Sandwich was evaluated by standard peel strength test and the metallurgical joint Aluminum Foam Sandwich panels had a higher peel strength. Moreover, a three-point bending fatigue test was conducted to study the flexural fatigue behavior of Aluminum Foam Sandwich panels. The metallurgical joint panels have a higher fatigue limit than the adhesive joining sandwich. Their fatigue fracture mode are completely different, the failure mode of the metallurgical joint is faced fatigue; the failure mode for the adhesive joint is debonding. Therefore, the higher joining strength leads to a longer fatigue life.

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.

Sign in / Sign up

Export Citation Format

Share Document