PROCEDURE AND SYSTEM FOR DECREASING LOCAL STRESSES IN TUBULAR ELEMENTS (VERSIONS) Russian patent published in 2010 - IPC F16L55/00 

FIELD: machine building.

SUBSTANCE: procedure for decreasing effect of local external load on tubular element consists in forming tubular element with external and internal layers; also internal layer is arranged radially inside relative to external layer. Further the procedure consists in placing force distributing material between the internal and external layer. This material possesses higher compliance in comparison with the internal layer and distributes local external shearing action onto the tubular element. Compressed fluid medium or compressed gel can be used as a force distributing material. The external layer can be moulded out of polymer material, or metal foil combined with non-organic layer or out of composite material. The system distributes local stress effecting the tubular element. Compliance property of the external layer causes its deformation relative to distributing force of material under effect of concentrated external load. The external compliant layer and force distributing material interact to isolate and protect the internal layer from shifts of surrounding underground material.

EFFECT: reduced local stresses in tubular elements.

22 cl, 9 dwg