This structure is provided with a first composite material 11, a second composite material 12 joined to the first composite material 11 by a film adhesive 21 provided between the first composite material 11 and the second composite material 12, and a corner fillet part 13 provided on a corner part 15 formed by the first composite material 11 and the second composite material 12. The shape of the corner fillet part 13 is a design shape P designed in advance, and the corner fillet part 13 is formed by curing the film adhesive 21 after arranging the film adhesive 21 on the corner part 15 so as to fit into the design shape P.

A system for producing a multiple layer material (49), comprising first and second corrugation rolls (14, 15) for providing a corrugated profile (16) having a plurality of crests (47), wherein the system further comprises first and second press rolls (21, 22) for applying a material sheet (19, 20) to crests (47) of the corrugated profile (16), and a plurality of heating members (28) arranged between the press rolls (21, 22) for welding the material sheet (19, 20) to the crests (47) of the corrugated profile (16) to form the multiple layer material (49). A guiding plate (48) is arranged between the corrugation 10 rolls (14, 15) and the heating members (28). The guiding plate (16) is arranged with a profile engaging side (50) having a plurality of crests (52) corresponding to the crests (47) of the corrugated profile (16). A cooling arrangement is provided for cooling the guiding plate (48). A method for producing the multiple layer material (49) is also disclosed.

A hollow core sheet having a plurality of channels and at least one bendable reinforcement rod adapted in width and thickness to a given channel dimensions for insertion inside a channel wherein the method of insertion consists in the steps of having the at least one bendable reinforcement rod having either or both of the width or the thickness having an outer dimension (OD) set between 0.50 0.75 of the given dimension of the channel with a variation of 5%.

A method of anchoring a connector in a first object includes providing the connector, the connector having a liquefiable material that is liquefiable by mechanical vibration, such as a thermoplastic material, bringing the connector into contact with low density layer that has an arrangement of discrete elements and gas-filled (empty) spaces between the discrete elements, pressing the connector against the low density layer and coupling mechanical vibration energy into the connector to cause the connector to penetrate into the low density layer to deform the discrete elements, until a flow portion of the liquefiable material becomes flowable and is caused to interpenetrate spaces between the deformed discrete elements so that an intertwined structure of the liquefiable material and the deformed discrete elements results, and stopping the mechanical vibration energy and causing the flow portion to re-solidify to anchor the connector in the low density layer.

The invention relates to a method for producing a folding core (50, 190, 300, 360, 370, 380) for a lightweight structure, wherein in a first method step bending lines (70, 170, 180) are applied onto a deformable flat semi-finished product (40).

A hollow core sheet having a plurality of channels and at least one bendable reinforcement rod adapted in width and thickness to a given channel dimensions for insertion inside a channel wherein the method of insertion consists in the steps of having the at least one bendable reinforcement rod having either or both of the width or the thickness having an outer dimension (OD) set between 0.50 0.75 of the given dimension of the channel with a variation of 5%.

A plastic laminated structure includes a plate member of plate-shaped fiber-reinforced plastic and a core member of trapezoidal-wave-shaped fiber-reinforced plastic. The plate member includes a thermoplastic resin and reinforcing fibers embedded in the thermoplastic resin. The core member is thermally bonded to the plate member, and includes a thermoplastic resin and reinforcing fibers that is embedded in the thermoplastic resin. A part of or the entire area of a main surface of the plate member includes smooth and rough surfaces. The rough surface has larger roughness than the smooth surface. The smooth and rough surfaces are alternately arranged in stripes.

A method of anchoring a connector in a first object includes providing the connector, the connector having a liquefiable material that is liquefiable by mechanical vibration, such as a thermoplastic material, bringing the connector into contact with low density layer that has an arrangement of discrete elements and gas-filled (empty) spaces between the discrete elements, pressing the connector against the low density layer and coupling mechanical vibration energy into the connector to cause the connector to penetrate into the low density layer to deform the discrete elements, until a flow portion of the liquefiable material becomes flowable and is caused to interpenetrate spaces between the deformed discrete elements so that an intertwined structure of the liquefiable material and the deformed discrete elements results, and stopping the mechanical vibration energy and causing the flow portion to re-solidify to anchor the connector in the low density layer.

A system for producing a multiple layer material (49), comprising first and second corrugation rolls (14, 15) for providing a corrugated profile (16) having a plurality of crests (47), wherein the system further comprises first and second press rolls (21, 22) for applying a material sheet (19, 20) to crests (47) of the corrugated profile (16), and a plurality of heating members (28) arranged between the press rolls (21, 22) for welding the material sheet (19, 20) to the crests (47) of the corrugated profile (16) to form the multiple layer material (49). A guiding plate (48) is arranged between the corrugation 10 rolls (14, 15) and the heating members (28). The guiding plate (16) is arranged with a profile engaging side (50) having a plurality of crests (52) corresponding to the crests (47) of the corrugated profile (16). A cooling arrangement is provided for cooling the guiding plate (48). A method for producing the multiple layer material (49) is also disclosed.

This structure is provided with a first composite material 11, a second composite material 12 joined to the first composite material 11 by a film adhesive 21 provided between the first composite material 11 and the second composite material 12, and a corner fillet part 13 provided on a corner part 15 formed by the first composite material 11 and the second composite material 12. The shape of the corner fillet part 13 is a design shape P designed in advance, and the corner fillet part 13 is formed by curing the film adhesive 21 after arranging the film adhesive 21 on the corner part 15 so as to fit into the design shape P.