Novel Honeycomb Construction
Publication Date: 2010-Jul-22
The IP.com Prior Art Database
Several new and novel honeycombs have been developed which have improved mechanical properties relative to their conventional counterparts. Specifically, these new configurations have improved compression after impact (CAI properties. These toughened materials perform extremely well in impact energy tests with good energy rebound and reduced impact damage.
NOVEL HONEYCOMB CONSTRUCTION
Several new and novel honeycombs have been developed which have improved mechanical properties relative to their conventional counterparts. Specifically, these new configurations have improved compression after impact (CAI) properties. These toughened materials perform extremely well in impact energy tests with good energy rebound and reduced impact damage.
Honeycombs are widely used in a variety of applications where a light weight, strong structure is advantageous. These applications include structures for the aircraft/aerospace market, the recreational market and the construction market. Generally, honeycomb is sandwiched between an upper and lower panel and which is referred to as a honeycomb sandwich panel. The upper and lower panels components are often referred to as honeycomb “skins”. There are a number of honeycomb configurations which are directed to achieving a higher strength to weight ratio when compared to a conventional hexagonal honeycomb configuration. Examples of some of these are referred to as “over expanded”, “tubular core”, “chevron core”, “flex core”, “corrugated core”, “truss core” and “specialty cores”.
Conventional honeycomb sandwich panels perform relatively poor in impact performance compared to solid composite laminates. Testing shows conventional honeycomb sandwich panels endure deeper surface dents and greater skin fractures upon impact than either a sandwich panel having a solid laminate skin with a strong honeycomb core or a solid laminate construction. The residual compression after impact (CAI) strength is an important consideration in aircraft components to allow safe flight with a structure in a damaged condition. Most honeycomb structures do not have the desired CAI strength to withstand the damage from severe impact events. A strong, tough honeycomb core configuration is required to minimize damage to a sandwich panel from severe impact and to provide a component, particularly in aircraft applications, which can be produced reliably at an acceptable cost.
In an attempt to improve the strength to weight ratio and the CAI strength over known honeycomb geometries , four new honeycomb configurations have been developed. These are referred to as “BIAXIAL TRUSS WEB”’ “SURFACE STIFFENED TRUSS WEB”, “QUASI-ISOTROPIC CROSS CORE” AND “SURFACE STIFFENED CHEVRON CORE honeycombs.
BIAXIAL TRUSS WEB honeycomb is a modified truss web construction. A base truss web geometry can best be described as a folded series of alternating V’s and Λ’s. The biaxial truss web configuration is a truss web imposed and integrated 90° on the top of an adjacent truss web. (See Fig. 1)To accommodate the imposed truss web, the lay-flat shape of adjacent web is cut to resemble a “bow tie” configuration prior to the alternating folding and subsequent integration onto the base truss web. A sepa...