Numerical and Experimental Investigation of Mechanical Behavior of Carbon and Glass Fiber Reinforced Composites and Honeycomb Sandwich Panels and its application in MALE UAV Wing Skin
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Fahad ALI (PAKISTAN), Raees RAEES FIDA SWATIAbstract :
Composites have fast gained popularity in replacing traditional materials in aerospace industry. Composites combine the properties of two or more constituent materials in order to achieve improved strength, stiffness, toughness and reduced weight. Properties can be altered by varying the constituents of the composites i.e. the fibers and the matrix. Carbon fiber Reinforced Composites (CFRP’s) play a pivotal role in developing lightweight aerospace structures. These are relatively expensive but are efficient to design structures where high strength to weight ratio is required with appropriate stiffness. Common applications include aerospace vehicles, spacecraft, ships, civil structure engineering, sports and electrical accessories etc. On the other hand, nomex honeycomb is a novel material developed in 1960’s and commercialized in 1970’s. It is formed by nomex paper, which is typically a form of aramid fiber similar to that of Kevlar. Subsequently, it is then dipped in phenolic resin to give high strength and toughness. The idea here is to draw a comparison of strength to weight ratio of simple carbon-carbon structure and honeycomb sandwich panels with nomex honeycomb as core and edges are of either carbon-carbon bi-directional composite or glass-glass bi-directional composite by applying suitable boundary conditions in experimental testing as well as in commercial software [1]. The analysis and detailed experimentation is carried out according to ASTM standards and validated accordingly.
. By increasing the width, height and thickness according to the ASTM standards, a parametrization study has also been conducted. The impact on the mechanical behavior of
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the sandwich panels such as core shear strength, edgewise compressive strength and flatwise compressive strength by changing the honeycomb core material and the filament material on the edge has also been investigated.
Hence, it is concluded that comprehensive testing of carbon-carbon, glass-glass fibers samples respectively showed that the strength to weight ratio has reduced drastically as for a certain thickness more layers are to be added to achieve the required strength which increases the weight penalty. Contrary to that, the presence of a nomex honeycomb core of 8 mm thickness between glass-glass bi-directional fibers can give optimum strength required for a detailed skin covering for a MALE UAV with mitigated weight penalty.
. By increasing the width, height and thickness according to the ASTM standards, a parametrization study has also been conducted. The impact on the mechanical behavior of
ix
the sandwich panels such as core shear strength, edgewise compressive strength and flatwise compressive strength by changing the honeycomb core material and the filament material on the edge has also been investigated.
Hence, it is concluded that comprehensive testing of carbon-carbon, glass-glass fibers samples respectively showed that the strength to weight ratio has reduced drastically as for a certain thickness more layers are to be added to achieve the required strength which increases the weight penalty. Contrary to that, the presence of a nomex honeycomb core of 8 mm thickness between glass-glass bi-directional fibers can give optimum strength required for a detailed skin covering for a MALE UAV with mitigated weight penalty.