Monolithic hurricane resistant structural panels made from low density composites

Abstract

A three dimensional composite panel structure is provided having a thickness less than about 22.5 cm, overall density less than 0.2 g / cm, and exhibiting a global modulus greater than 1.2 GPa and stiffness greater than 15 kN-m2. The composite panel structure includes at least two fiber-reinforced mats interconnected in a spaced substantially parallel configuration by a skeletal web and a closed cell foam filling the spaces between the panels. The fiber-reinforced mats include a plurality of fibers in a low viscosity cured thermosetting resin matrix.

Description

RELATED APPLICATIONS [0001] This application claims the benefit of provisional application Ser. No. 60 / 512,546 filed Oct. 17, 2003, the contents of which are fully incorporated herein by reference.U.S. GOVERNMENT RIGHTS [0002] This invention was made under a project entitled Affordable Composites from Renewable Sources sponsored by the National Science Foundation (NSF) and the Department of Energy (DoE).FIELD OF THE INVENTION [0003] This invention relates to a lightweight composite structure and more particularly to a lightweight monolithic composite structure and the method for manufacturing such structure for use as a structural element including a roof in a hurricane resistant building. BACKGROUND OF THE INVENTION [0004] Over the past fifteen years, the United States has experienced three major hurricanes, Hugo (1989), Andrew (1992), and Iniki (1992), causing over $27.5 billion dollars cumulatively in damage to insured property. Typically, when houses are exposed to hurricane for...

AI Technical Summary

Benefits of technology

The present invention provides a composite panel structure that has a three-dimensional structure with thickness less than about 22.5 cm, overall density less than 0.2 g / cm, and exhibits a global modulus greater than 1.2 GPa and stiffness greater than 15 kN-m2. The panel structure comprises at least two fiber-reinforcing mats interconnected in a spaced substantially parallel configuration by a skeletal web. A closed cell foam fills the spaces between the panels. The mats comprise a plurality of fibers in a resin matrix. The composite panel structure has high thermal resistance R-value due to its high content of foam insulation. These structures can be used as roofs or walls and are manufactured by VARTM or similar processes. They can also be produced in other planar or curved designs for other applications.

Problems solved by technology

Typically, when houses are exposed to hurricane forces, the roofs are most susceptible to damage, followed by walls, and then foundations.

The most common roof damage is the loss of cladding or sheathing (tiles, shingles, etc.) resulting from the very high suction pressures that develop at the roof / wall interface.

Once the sheathing is lost, the roof no longer acts as a diaphragm, and the lateral load carrying ability of the structure is compromised.

In addition, the loss of sheathing can result in costly water damage, as particularly noticed with hurricane Andrew.

Such methods of construction are time consuming and require the use of numerous crews of highly skilled tradesmen to complete each segment of the project.

Such structure again requires on-site labor and therefore increased costs.

Furthermore, the concrete and steel rods add substantial weight to the structure requiring substantial supports.

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