Damage-tolerance testing method for whole wing spar of airplane

Abstract

The invention pertains to airplane fatigue and damage-tolerance testing technologies, and relates to a damage-tolerance testing method for the whole wing spar of an airplane. The method comprises the steps of: (I) choosing a part with large load from the whole wing spar for serving as a testing part examining segment, (II) producing two same testing parts according to the examining segment, (III) reserving an interval of 20 to 30mm between the two back-to-back testing parts which are respectively provided with a coating in the upper part and the lower part (the coating is connected with an upper spar edge strip and a lower spar edge strip to form a case segment), (IV) fixing the root of the testing case segment completing assembly on a load-bearing wall, (V) exerting concentrated load at one end of the testing parts to simulate the bending moment of the spar at the testing segment and the shearing force of a web, without considering the influence of the shearing flow of the coating and (VI) using a finite element method to conduct damage tolerance analysis on the testing parts and comparing testing results. The method solves the difficulty that the crack expansion and remaining strength of the present airplane whole wing spar structure lack theoretical evidence; and the design of the testing parts adopts a method of simultaneously conducting tests to the two back-to-back testing parts, thereby eliminating the distortion of a single spar.

Description

technical field [0001] The invention belongs to the aircraft fatigue damage tolerance test technology, and relates to a damage tolerance test method of an aircraft integral wing spar. Background technique [0002] Aircraft structures can generally be divided into integral structures and combined structures. At present, the research on the calculation of stress intensity factor and the application of damage tolerance performance of combined structures is relatively in-depth and extensive at home and abroad, but there are few related studies on the overall structure, let alone the application; some foreign literature has passed Experiments and finite element analysis have been carried out on the fracture characteristics of integrally stiffened plates and variable thickness integral wall plates, and some literatures have studied the stress intensity factor and crack trajectory of integral spars through finite element analysis; According to the literature data, the damage toler...

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Problems solved by technology

At present, the research on the calculation of stress intensity factor and the application of damage tolerance performance of combined structures is relatively in-depth and extensive at home and abroad, but there are few related studies on the overall structure, let alone the application; some foreign literature has passed Experiments and finite element analysis have been carried out on the fracture characteristics of integrally stiffened plates and variable thickness integral wall plates, and some literatures have studied the stress intensity factor and crack trajectory of integral spars through finite element analysis; According to the literature data, the damage tolerance test research on the overall spar structure has not been seen, the theoretical research on the damage tolerance of the overall structure is also very scarce, there is basically no special experimental research, there is a great lack of theoretical calculation analysis, and a lack of experimental data. Supporting and comparative analysis, the regularity of the damage tolerance characteristics of the overall spar structure cannot be fully understood and grasped in the structural design, and there is still a considerable gap with the requirements of engineering applications

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