Bonded Structures

structures that consist of elements formed by adhesive bonding and joined by bonded joints or joints of other types. There are architectural, marine (bodies of motor-boats, rowboats, and other vessels), and aviation (helicopter fuselages and certain other types of aircraft) bonded structures. Modern synthetic adhesives make possible the joining of materials of different types (for example, wood or concrete and metal) used in bonded structures.

The most widespread bonded structure is the architectural type, which includes supporting and exterior structures. Supporting bonded structures, which are usually made of wood or plywood, have a variety of shapes, such as beams, frames, arches, and girders. Exterior bonded structures, which combine the functions of supporting and insulating wall elements and roofing, are usually in the form of sandwich panels with exterior sheathing made from a strong sheet material bonded to internal ribs or to an intermediate layer of a low-density material. Among the materials used as sheathing are aluminum, plywood, asbestos cement, and glass-fiber-reinforced plastics based on synthetic binders (phenol, polyester, and epoxy resins). The intermediate layer may be continuous, made of foam plastic (polystyrene, phenol, polyurethane, or polyvinyl chloride), or cellular (usually hexagonal), made from cardboard or from paper impregnated with a synthetic resin. Other varieties of bonded structures consist of synthetic fabrics based on adhesive compounds, which are used as coverings for temporary structures (for example, grain storehouses) or as shelters during construction work.

Further improvement of bonded structures depends on increased strength and improved heat resistance and durability in various climates, particularly in the Far North, where supporting and exterior bonded structures are very effective because of their low weight, increased rigidity, and transportability.