Mandziuk S. Torsion accounting in the fatigue life calculation of aircraft wing structure on the flight modes

Object - fatigue resistance elements of the wing structure, loaded by combination of the shear force, bending and torsion moments. The aim is the development and justify the method of calculation of the fatigue life of the wing structure at a non-proportional loading of bending and torsion on the airplane flight regimes. Methods that used are method of durability calculation by the local stress-strain state and the nominal stress, finite element method, tensometric method. Practical outcomes: the developed method allows for calculation of the fatigue life of the wing structure at a non-proportional action of shear force, bending and torsion moments on the airplane flight modes. Novelty - improved method of calculation of the fatigue life of the aircraft wing structure elements due to the fact that in contrast to the existing methods it takes into account the fatigue damage along the stress concentrator contour. This allows to significantly increase the accuracy of prediction of durability and a resource at a non-proportional force loading factors; has been further developed method for of calibration of prepared cross sections of an aircraft wing for measuring force factors in flight due to a prior determination by the method of finite element areas where the hypotheses and assumptions of the calculation scheme thin-walled bar, is advisable to install strain gauges; first proposed method of calculating the the general stress state of the wing structure, due to reasonable use of the beam analogy; improved method for determining the integral force factors along a wingspan according to flight measurements, in contrast to the known method takes into account the balancing load on the horizontal tail on the flight modes. The degree of implementation - the main results of the dissertation are used at the State Enterprise "Antonov" aircraft repair enterprise "URARP" in the educational process of the National Aerospace University "Kharkiv Aviation Institute". Industry sector - aircraft manufacturing.