Abstract: A rotorcraft includes a fuselage, rotors and circular wings. The rotors are attached to the fuselage. The rotors are attached to the fuselage. The circular wings are disposed under the rotors respectively. Upper surfaces of the circular wings have annular curved surfaces and thereby are convex upward respectively. The circular wings cause Coanda effects by the upper surfaces respectively. First lift is generated by rotating the rotors. Second lift is generated by the Coanda effects by the circular wings. Third lift is generated by air jets deflected downward along the upper surfaces of the circular wings respectively.

Abstract: A method of designing an anisotropic composite laminate structure to constitute a predetermined member of an airframe structure of an aircraft and includes a plurality of types of composite layers containing reinforcing fibers with different fiber orientations is provided. The method includes dividing the anisotropic composite laminate structure in the predetermined member into a plurality of regions in a thickness direction. The method includes determining, for each of the regions, at least a stacking sequence of the plurality of types of composite layers in accordance with a direction of stress acting on the predetermined member.

Abstract: A load calculator includes a coefficient storage, a replacement deriver, and an internal-load deriver. The storage stores a first coefficient, an internal load acting on a target point in a target member when a unit load acts on a concentrated load point in the target member along one of three orthogonal axes, and as a second coefficient, an internal load acting on the target point when a unit moment acts on the concentrated load point around one of the axes. The replacement deriver derives a replacement load and moment by replacing an external load acting on the target member with six force components acting on the concentrated load point. The internal load deriver derives an internal load acting on any target point with the first coefficient, the replacement load, the second coefficient, and the replacement moment when the external load acts on the target member.

Abstract: A method of designing an anisotropic composite laminate structure to constitute a predetermined member of an airframe structure of an aircraft and includes a plurality of types of composite layers containing reinforcing fibers with different fiber orientations is provided. The method includes dividing the anisotropic composite laminate structure in the predetermined member into a plurality of regions in a thickness direction. The method includes determining, for each of the regions, at least a stacking sequence of the plurality of types of composite layers in accordance with a direction of stress acting on the predetermined member.

Abstract: There is provided a method of manufacturing a composite structure of an aircraft. The composite structure includes a skin and a reinforcing material. The method includes, by stacking unhardened composite sheets on a region of a jig adjacent to a holding portion to hold the reinforcing material, forming a skin inner layer including a retainer to retain two end portions of a flange of the reinforcing material in a width direction of the flange. The method includes installing the reinforcing material at the holding portion of the jig so that the two end portions abut upon the retainer. The method includes, by stacking unhardened composite sheets on an outer surface of the flange and on an outer surface of the skin inner layer, forming a skin outer layer. The method includes hardening the skin inner layer and the skin outer layer.

Abstract: A joint structure includes a first member having a fit-in groove, a second member made of a material different from a material of the first member and having an insertion section to be inserted into the fit-in groove, and a plurality of bonding layers having different hardness and formed between the fit-in groove and the insertion section.

Abstract: A flight restriction setting system includes a damage detector and a flight restriction calculator. The damage detector is configured to detect damage caused to a structure constituting an aircraft. The flight restriction calculator is configured to set flight restriction on the aircraft according to a degree of the damage detected by the damage detector.

Abstract: A joint structure includes a first member and a second member. The first member includes a projection having a distal end and a base end. The distal end is thicker than the base end. The second member is made of a material different from a material of the first member and has a fitting groove into which the projection is to be inserted. The projection includes, on its surface, an inclined surface extending from the distal end to the base end and inclined with respect to a facing direction in which the first member and the second member face each other. The projection at least includes a plurality of fiber-containing layers that each have a sections in which a fiber extends along the inclined surface.

Abstract: A joint structure includes a first member having a fit-in groove, a second member made of a material different from a material of the first member and having an insertion section to be inserted into the fit-in groove, and a plurality of bonding layers having different hardness and formed between the fit-in groove and the insertion section.

Abstract: A load calculator includes a coefficient storage, a replacement deriver, and an internal-load deriver. The storage stores a first coefficient, an internal load acting on a target point in a target member when a unit load acts on a concentrated load point in the target member along one of three orthogonal axes, and as a second coefficient, an internal load acting on the target point when a unit moment acts on the concentrated load point around one of the axes. The replacement deriver derives a replacement load and moment by replacing an external load acting on the target member with six force components acting on the concentrated load point. The internal load deriver derives an internal load acting on any target point with the first coefficient, the replacement load, the second coefficient, and and the replacement moment when the external load acts on the target member.

Abstract: A joint structure includes a first member and a second member. The first member includes a projection having a distal end and a base end. The distal end is thicker than the base end. The second member is made of a material different from a material of the first member and has a fitting groove into which the projection is to be inserted. The projection includes, on its surface, an inclined surface extending from the distal end to the base end and inclined with respect to a facing direction in which the first member and the second member face each other. The projection at least includes a plurality of fiber-containing layers that each have a sections in which a fiber extends along the inclined surface.

Abstract: According to one implementation, a flight restriction setup system includes a damage detection unit and a flight restriction calculation unit. The damage detection unit detects a damage which arose in a structure composing an aircraft. The flight restriction calculation unit sets at least one flight restriction of the aircraft according to a degree of the damage detected by the damage detection unit. Further, according to one implementation, a flight restriction setup method includes: detecting a damage, which arose in a structure composing an aircraft, by a damage detection unit; and setting a flight restriction of the aircraft according to a degree of the damage detected by the damage detection unit.

Abstract: A flight restriction setting system includes a damage detector and a flight restriction calculator. The damage detector is configured to detect damage caused to a structure constituting an aircraft. The flight restriction calculator is configured to set flight restriction on the aircraft according to a degree of the damage detected by the damage detector.

Abstract: According to one implementation, a flight restriction setup system includes a damage detection unit and a flight restriction calculation unit. The damage detection unit detects a damage which arose in a structure composing an aircraft. The flight restriction calculation unit sets at least one flight restriction of the aircraft according to a degree of the damage detected by the damage detection unit. Further, according to one implementation, a flight restriction setup method includes: detecting a damage, which arose in a structure composing an aircraft, by a damage detection unit; and setting a flight restriction of the aircraft according to a degree of the damage detected by the damage detection unit.