Structural analysis of aircraft structuresIntroductionAirplanes are generally built from components such as wings, fuselages, empennages, engines, control surfaces of flight, stabilizers, a main rotor assembly, a tail rotor assembly and a landing. gears with a few exceptions depending on the design. Each component has one or more categorical functions and must be designed to ensure that it can perform these functions safely. A fixed-wing aircraft has wings, fuselages, engines, flight control surfaces, stabilizers and landing gear and a rotary-wing aircraft has a main rotor assembly, a tail rotor assembly, fuselages, engines and landing gear. A good aircraft structure is one that provides all the strength and rigidity necessary to enable the aircraft to meet all of its design requirements, but weighs no more than necessary. Important factors to consider in aircraft structures are strength, weight and reliability which determine the requirements that any material used in the construction or repair of the aircraft must meet. The cells must be light and strong. All materials used in the construction of an aircraft must be reliable. Reliability minimizes the possibility of dangerous and unexpected failures. Many structural forces and stresses act on an aircraft in flight and on the ground. When on the ground, the force of gravity creates weight, which is reinforced by the landing gear. The landing gear absorbs the forces imposed on the aircraft during takeoffs and landings. Any maneuver causing acceleration or deceleration during flight increases the forces and stresses on the wings and fuselage. The stresses acting on the wings, fuselage and landing gear are tension, compression, bending, shear and torsion. The resulting stresses...... middle of paper ......) are calculated for a given hull gauge pressure which is typically 12 psig. For the fuselage, the distributions of longitudinal bending moments are examined from three load cases. Loads are calculated for a quasi-static traction maneuver, a landing maneuver and movement over runway bumps. There are a variety of structural geometries available for the fuselage. There is a concept of a simply stiffened shell using longitudinal frames. There are three concepts with Z-stiffened hulls and longitudinal frames; one with proportioned structural material to give minimum buckling weight, one with compromised buckling efficiency to give lighter weight with minimum buckling, and one with compromised buckling pressure. Likewise, there are three lattice core sandwich designs, two for minimum buckling weight with and without frames, and one for minimum buckling gauge compromise..