Optimization of the manufacturing parameters of honeycomb composite sandwich structures for aerospace application (original) (raw)
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Lightweight composite sandwich structures are laminated composite structures that are composed of thin stiff face sheets bonded to a thicker lightweight core in between. These structures have high potential to be used in marine, aerospace, defense and civil engineering applications due to their high strength to weight ratios and energy absorption capacity.In this study, composite sandwich structures were developed with carbon fiber reinforced polymer composite face sheets and aluminum honeycomb core materials with various thicknesses. Carbon fiber/epoxy composite face sheets were fabricated with lamination of [0/90]s carbon fabrics by vacuum infusion technique. Al honeycomb layers were sandwiched together with the face sheets using a thermosetting adhesive. Mechanical tests were carried out to determine the mechanical behavior of face sheets, Al cores and the composite structure. Effect of core thickness on the mechanical properties of the sandwich was investigated.
Design, Modelling and Manufacturing aspects of Honeycomb Sandwich Structures: A Review
Honeycomb sandwich panels are widely used in automobile, aerospace and space structures due to unique characteristics like high strength to weight ratio and High stiffness. Honeycomb sandwich panels consist of honeycomb core made of either metal or thin paper like materials. Core is sandwiched with metallic or composite face sheets. Core gives high compressive strength in T direction whereas face sheet gives shear strength in T and W direction. Compressive strength of sandwich panel depends on foil thickness of honeycomb core, cell size, thickness of core in T direction and face sheet thickness. For nearly same weight honeycomb sandwich panels can give up to 30 times higher stiffness than metallic sheets. Face sheets of the sandwich structure facilitate mounting of the instruments as core has very high volume fraction of cavity and hence cannot hold fasteners alone.Modelling of Honeycomb sandwich structures with actual cell configuration is difficult and time consuming. Hence sandwi...
Sandwich panels are composites which consist of two thin laminate outer skins and lightweight (e.g., honeycomb) thick core structure. Owing to the core structure, such composites are distinguished by stiffness. Despite the thickness of the core, sandwich composites are light and have a relatively high flexural strength. These composites have a spatial structure, which affects good thermal insulator properties. Sandwich panels are used in aeronautics, road vehicles, ships, and civil engineering. The mechanical properties of these composites are directly dependent on the properties of sandwich components and method of manufacturing. The paper presents some aspects of technology and its influence on mechanical properties of sandwich structure polymer composites. The sandwiches described in the paper were made by three different methods: hand lay-up, press method, and autoclave use. The samples of sandwiches were tested for failure caused by impact load. Sandwiches prepared in the same way were used for structural analysis of adhesive layer between panels and core. The results of research showed that the method of manufacturing, more precisely the pressure while forming sandwich panels, influences some mechanical properties of sandwich structured polymer composites such as flexural strength, impact strength, and compressive strength.
Design of Sandwich Composites with Multi-Functional Facesheets
MRS Proceedings, 2001
ABSTRACTSandwich composites find increasing use as flexural load bearing lightweight sub-elements in air / space vehicles, rail / ground transportation, marine and sporting goods. The core materials in these applications is usually balsa, foam or honeycombs, while laminated carbon or glass are used as facesheets. A limitation of traditional sandwich configurations is that the space in the core becomes inaccessible once the facesheets are bonded in place. Significant multi-functional benefits can be obtained by making either the facesheets or the core, space accessible. Multi-functionality is generally referred to as value added to the structure that enhances functions beyond traditional load bearing. Such functions may include sound / vibration damping, ability to route wires or embed sensors. The present work considers traditional core materials of nomex and aluminum honeycombs that possess functional space accessible facesheets, and their low velocity impact (LVI) response.
Sandwich Composite for UAV Wing Design and Fabrication
2018
The aerospace applications are bonded to the low weight and high structural strength necessity, this lead to the more research work in the field of composites. The composites hold the more strength to weight ratio compared to the other conventional materials. Their strength mainly depends on the orientation of the reinforcement material and volume fraction of matrix and reinforcement. The sandwich composites are extensively used in the aerospace applications where a conventional material’s strength is increased by adding the layers of composite material by prescribed orientations. The different fabrication techniques and the selection factor for aero foil is discussed in the paper.
Numerical Modelling of a Composite Sandwich Structure Having Non Metallic Honeycomb Core
Evergreen, 2021
The composite sandwich structures are in great demand in aircraft, automotive and sports industries because these materials possess light weight, high flexural strength and stiffness. In present research paper, initially a composite sandwich structure, having Carbon Fibre Reinforced Plastic (CFRP) face sheets and a regular hexagon Kevlar® Honeycomb core material, in the form of an equivalent solid, has been modelled. 'Gibson and Ashbey' model for regular hexagon double wall thickness honeycomb core has been employed to determine the equivalent orthotropic properties of Kevlar® Honeycomb core. "Three point bend test (3PBT)" has been performed on sandwich panel using Ansys as per ASTM C393-00 standard and ultimate load and deformation have been calculated. Then for experimental result, a composite sandwich has been fabricated and a 3PBT also has been performed on it. The analytical value for deflection has also been found using the ASTM C 399-00 standard. The value of stiffness obtained from finite element model is successfully compared with the experimental and analytical solutions and the numerical model predict to an excellent stage of the static behaviour of the material whilst compared with the experiments.
MechAero Foundation for Technical Research & Education Excellence, 2022
Composite sandwich panels are progressively being employed in the aircraft industry for floor panels, compartment partitions, bulkheads and even the skin and wings of aircraft. Lightweight structures are essential for aircraft operations because they allow for faster takeoff and landing. The sandwich panel comes into play in this situation. Composites with stiff, high-strength skin facings are bonded to a low-density core to form multi-layered materials with a high mechanical strength. Using finite element analysis and experimental equipment, composite sandwich panels are constructed, tested and evaluated under various load circumstances. The panel's expected compressive strength and flexural stiffness values were then calculated for various operating conditions. A mean difference of 0.28 is seen between the stresses in both x and y directions of the panel over a loading range of 1kg to 60kg. The standardised values of the strains were used to compare them using Bayesian estimation, which outperforms the t test. Ec increases by nearly 20 times when the side length is increased by 10% compared to when the side length is increased by 50%. For a given span length and when an is fixed, the flexural stiffness at f1=0.002 is nearly 2 times higher than that at f1=0.006. Although there are differences in the displacements and strains, the overall trend is fairly pleasing. The exact numerical conditions were not produced due to the experimental challenges, but the loading and displacements were equal.
Mechanical performance of 3D-printing plastic honeycomb sandwich structure
International Journal of Precision Engineering and Manufacturing-Green Technology, 2018
In this study, Bi-Grid, Tri-Grid, Quadri-Grid and Kagome-Grid honeycombs were designed and fabricated using 3D printing technology Sandwich composites were prepared by gluing the cores and composite face sheets together. Mechanical performance of the sandwich structures were characterized using finite element analysis and three-point bending test. Results indicate that when suffering from bending loads, the stress concentrations are located at the loading zone on upper face sheets (distributed in both sides of the indenter) and supporting zone on bottom face sheets, and the stress concentration zones of the honeycomb cores are located in the area that between indenter and supports. The failure mechanism of the Bi-Grid sandwich structure is interfacial de-bonding between composite face sheet and Bi-Grid core, and the failure modes of the Tri-Grid, Quadri-Grid and Kagome-Grid are core shear. The mechanical performance of Quadri-Grid sandwich structure is better than that of the other three structures.
Development of a sandwich material with polypropylene/natural fibre skins and paper honeycomb core
Honeycomb sandwich materials are well-known in many aerospace applications. However, honeycombs are also used as door fillings, as packaging protection elements and in the automotive industry. Those honeycombs are made from unimpregnated low cost papers. The high production costs and the low production capacities limit the use of those paper honeycombs in semi-structural applications like the automotive interior. More cost efficient paper honeycombs could replace foam cores (polyurethane foams) in many automotive applications. Recently a new cost efficient paper honeycomb material and its continuous production process have been developed, which enables an automated in-line production of paper based honeycombs. The combination of this low cost paper honeycomb core and a polypropylene/natural fibre material for the skins is the subject of the present study. This material combination was investigated because the resulting sandwich panel is not only light weight and cost efficient but also renewable resource based and fully recyclable.
Laboratory Study of Polypropylene-based Honeycomb Core for Sandwich Composites
Spektrum Industri, 2021
Article history : The polypropylene-based honeycomb core is one of the most common hybrid materials currently used to reinforce the structure of sandwich composites. This material is widely used in various science, technology, and engineering fields, including aerospace applications, due to its high strength properties. Therefore, this research evaluated the mechanical properties of the well-known hybrid composites of carbon fiber (CF) and glass fiber (GF) under reinforced sandwich composites. The different curingpressure values of each material were analyzed to determine the pressure responsible for the superior performances and properties. The specimens were moulded using the hand lay-up or cloth laying angle technique of the carbon fiber. Furthermore, by changing direction, the greatest load-bearing direction based on the bending test was determined. According to the ASTM standard on strength determination, an increase in curing pressure leads to a rise in flexural stress. By placing the material orientation in the right order (i.e., [CF90/CF0/GF0/Core/GF0/ CF0/GF0]) the highest strength is obtained. However, when the strain reaches its maximum value, the fracture of the specimen, followed by the fiber orientation of the fabric. The experimental results showed that the lower the curing pressure, the thicker the workpiece decreased fiber volume fraction. The results also showed that changes in the curing pressure and laying angle affect the mechanical properties of the sandwich composites.