Failure Modes and Influence of theQuasi-static Deformation Rate on the Mechanical Behavior of Sandwich Panels with Aluminum Foam Cores

2010 ◽  
Vol 17 (5) ◽  
pp. 335-342 ◽  
Author(s):  
Isabel Duarte ◽  
F. Teixeira-Dias ◽  
Ana Graça ◽  
António J. M. Ferreira
Keyword(s):  
Mechanical Behavior ◽  
Deformation Rate ◽  
Aluminum Foam ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Static Deformation

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.

Dynamic Response of Aluminum Foam Sandwich Panel to Transverse Impact

2013 ◽  
Vol 535-536 ◽  
pp. 485-488
Author(s):  
Zhi Hua Wang ◽  
Xin Li ◽  
Zhi Qiang Li ◽  
Long Mao Zhao
Keyword(s):  
Dynamic Response ◽  
Aluminum Foam ◽  
Failure Modes ◽  
Shear Failure ◽  
Metal Foam ◽  
Sandwich Panels ◽  
Front Face ◽  
Strain History ◽  
Transverse Impact ◽  
Cell Foam

The dynamic response of aluminum foam sandwich panels are studied experimentally by impacting the panels at mid-span with metal foam projectiles. Two types of core are considered: open-cell foam and closed-cell foam. By changing the launching speed of metal foam projectiles, different deformation/failure modes of sandwich panels are obtained. Strain history of face sheets in different positions is also recorded by strain gauges to observe its deformation mechanism. The experiment results indicated that when the strength of core is relatively small and the impulse exerted is large, erosion failure of front face and shear failure of core occurred.

Flexural response of carbon fiber reinforced aluminum foam sandwich

2017 ◽  
Vol 52 (14) ◽  
pp. 1887-1897 ◽  
Author(s):  
Chang Yan ◽  
Xuding Song ◽  
Hui Zhu ◽  
Chuanhe Jing ◽  
Shuo Feng
Keyword(s):  
Carbon Fiber ◽  
Energy Absorption ◽  
Aluminum Foam ◽  
Failure Modes ◽  
Peak Load ◽  
Sandwich Panels ◽  
Foam Core ◽  
Carbon Fiber Fabric ◽  
Final Failure ◽  
Fiber Fabric

Sandwich panels with carbon fiber fabric/epoxy resin face-sheet and aluminum foam core have a potential application value in the engineering field. To study the bending mechanical properties of the reinforced sandwich structure, three-point bending test was conducted by using WDW-T100 electronic universal tensile testing machine. The relation between load and displacement of the aluminum foam sandwich was obtained. Deformations and failure modes of the specimens were recorded. Scanning electron microscopy was used to observe the failure mechanism. Results showed that when aluminum foam was reinforced by carbon fiber fabric as face-sheet, its flexural load-carrying capacity and energy absorption ability improved significantly. Foam core density and number of carbon fiber plies had serious impacts on the peak load value and energy absorption value of the composite structure. It was suggested that aluminum foam core sandwich structure with low foam core density of 0.49 g/cm3 and 5 plies of carbon fiber fabric had the highest energy absorption ability and medium load-carrying ability. Failure modes analysis showed that shear failure leaded to the final failure of sandwich panels with medium peak load and interface de-bonding leaded to the final failure of sandwich panels with high peak load.

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.

scholarly journals Investigating the Effect of Interface Morphology in Adhesively Bonded Composite Wavy-Lap Joints

2021 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Roya Akrami ◽  
Shahwaiz Anjum ◽  
Sakineh Fotouhi ◽  
Joel Boaretto ◽  
Felipe Vannucchi de Camargo ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Composite Structures ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Tensile Load ◽  
Lap Joints ◽  
Load Level ◽  
Displacement Curve ◽  
Interface Morphology ◽  
Angle Variation

Joints and interfaces are one of the key aspects of the design and production of composite structures. This paper investigates the effect of adhesive–adherend interface morphology on the mechanical behavior of wavy-lap joints with the aim to improve the mechanical performance. Intentional deviation from a flat joint plane was introduced in different bond angles (0°, 60°, 90° and 120°) and the joints were subjected to a quasi-static tensile load. Comparisons were made regarding the mechanical behavior of the conventional flat joint and the wavy joints. The visible failure modes that occurred within each of the joint configurations was also highlighted and explained. Load vs. displacement graphs were produced and compared, as well as the failure modes discussed both visually and qualitatively. It was observed that distinct interface morphologies result in variation in the load–displacement curve and damage types. The wavy-lap joints experience a considerably higher displacement due to the additional bending in the joint area, and the initial damage starts occurring at a higher displacement. However, the load level had its maximum value for the single-lap joints. Our findings provide insight for the development of different interface morphology angle variation to optimize the joints behavior, which is widely observed in some biological systems to improve their performance.

scholarly journals The Bending Responses of Sandwich Panels with Aluminium Honeycomb Core and CFRP Skins Used in Electric Vehicle Body

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yong Xiao ◽  
Yefa Hu ◽  
Jinguang Zhang ◽  
Chunsheng Song ◽  
Xiangyang Huang ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Vehicle Body ◽  
Stacking Sequence ◽  
Honeycomb Core ◽  
Fibre Direction ◽  
Element Analysis ◽  
Honeycomb Sandwich ◽  
Carbon Fibre Reinforced Plastic

The aim of this paper was to investigate bending responses of sandwich panels with aluminium honeycomb core and carbon fibre-reinforced plastic (CFRP) skins used in electric vehicle body subjected to quasistatic bending. The typical load-displacement curves, failure modes, and energy absorption are studied. The effects of fibre direction, stacking sequence, layer thickness, and loading velocity on the crashworthiness characteristics are discussed. The finite element analysis (FEA) results are compared with experimental measurements. It is observed that there are good agreements between the FEA and experimental results. Numerical simulations and experiment predict that the honeycomb sandwich panels with ±30° and ±45° fibre direction, asymmetrical stacking sequence (45°/−45°/45°/−45°), thicker panels (0.2 mm∼0.4 mm), and smaller loading velocity (5 mm/min∼30 mm/min) have better crashworthiness performance. The FEA prediction is also helpful in understanding the initiation and propagation of cracks within the honeycomb sandwich panels.

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