Airbus (2001) stated that the honeycomb is an anisotropic body of relatively low gross density of reinforced material, phenolic resin and node adhesive with directional physical and mechanical properties. The L-direction (L) is the longitudinal direction of the honeycomb parallel to the bonded areas and perpendicular to 'h'. L is also known as the ribbon direction. The W-direction (W) is the direction perpendicular to L and h. W is also known as the direction of expansion. The 'h' dimension or honeycomb sheet thickness is the cell height. According to the core type, the cell size shall be as follow:
i. Hexagonal = Diameter of the circle inscribed within the cell. ii. Over-expanded = Distance between two parallel and opposite cell walls, measured…show more content… Other honeycombs (such as those made of paper and aluminium) are made by a multi-stage process. In these cases large thin sheets of the material (usually 1.2x2.4m) are printed with alternating, parallel, thin stripes of adhesive and the sheets are then stacked in a heated press while the adhesive cures. In the case of aluminium honeycomb the stack of sheets is then sliced through its thickness. The slices (known as 'block form') are later gently stretched and expanded to form the sheet of continuous hexagonal cell…show more content… This is the explanation of Kevlar honeycomb core. The length of the honeycomb core will be known as L-direction. The width or expansion of the honeycomb core will be known as W-direction. The cell size and height will be representing by “b” and “h” respectively. The plain view of honeycomb core configuration can be defined as below.
Based on information from Core Composites Inc. (2014),Kevlar is the newest addition the honeycomb line. It is an extremely lightweight, high strength, non-metallic honeycomb manufactured with para-aramid fiber paper (DUPONT Kevlar® N636 or equivalent). The para-aramid paper is impregnated with a heat resistant phenolic resin. This core material exhibits improved performance characteristics over Nomex® and Korex® in the areas of weight, strengths, stiffness and fatigue. Among advantages of Kevlar Honeycomb are:
• High Strength to Weight Ratio
• Up to a 40% Weight Savings vs Nomex
• Excellent Thermal and Moisture stability
• Improved Shear Strength & Modulus (4x stiffer than
