Xiaoyang Wu’s research while affiliated with Northwestern Polytechnical University and other places

In this paper, the carbon fiber composite stiffened panel is taken as the research object, and a mechanical simulation model including shear failure is established based on the progressive damage theory of composite materials and the theory of adhesive interface degradation. The effects of discrete low-velocity impact damage on buckling stability, ultimate bearing capacity and failure mode of stiffened panels are investigated by means of tests and finite element analysis. The invisible damage was introduced sequentially to three different locations of the stiffened panel using a drop hammer impact. It was found that the damage of matrix and fiber caused by low-velocity impact may lead to the change of stiffness and strength of the structure.

In this paper, based on the thermal effect of plasticity and friction work, the influence of different friction coefficients on energy transfer and thermal effect of the structure is fully considered. The dynamic response simulation model of fragments impacting the fuselage frame structure in tire burst mode is proposed. According to the impact speed specified by airworthiness, the fragments impact test of fuselage frame structure is carried out. The test and simulation results show that the impacted structure is more likely to produce stress concentration and damage in the parts with large stiffness change. Through the study of structural energy conversion and temperature change, it is found that plastic work contributes more to temperature change than friction work during impact. Moreover, there is no linear relationship between the difference of temperature rise and friction coefficient.

Based on the coupled Eulerian-Lagrangian (CEL) method, a dynamic response simulation model was proposed for the impact of tire burst debris on the aircraft fuel tank cover structure, which fully considered the interaction between the fuel tank cover structure and fuel. At least three tire debris impact tests were conducted on a typical fuel tank cover according to the airworthiness regulation speed, and the effects of internal air pressure and tank sloshing of the fuel tank cover during the impact were investigated. Through the experimental and numerical analysis of fuel tank sloshing, fuel pressure and plastic strain, it was found that the increase of fuel volume and impact position would have a serious impact on the safety during the impact of tire bursting debris on the fuel tank cover, and may course the fuel tank leak. The test method in this paper meets the airworthiness requirements, and the proposed impact simulation method can be used in the structural analysis and optimization design.

This paper presented the dynamic behavior of tire fragments and their impact on aluminum alloy plates by the methods of experiment and numerical simulation. In the experiment, the impacts of tire fragments on aluminum alloy plates under quadrilateral constraint, bilateral constraint and four-corner constraint were studied. According to the experimental results and based on Ogden model and Johnson-Cook model, a simulation calculation model for fragment impact was proposed. Analysis of plastic deformation area, failure mode, etc. verified that the proposed model could stimulate the impact of tire fragments on aluminum alloy plates. By comparing different constraint conditions, it is found that within the impact range, the plate under quadrilateral constraint can resist the strongest impact.

When a tire bursts, the flying fragments may break through the wing, damage the precision instruments inside it, and cause huge economic losses. In this paper, the impact of tire fragments on the fuselage structure is simulated, and the dynamic response of the structure under different postures of impacting different structures and fragments is analyzed. The damage caused by different impact modes is analyzed and compared, the harshest impact conditions are selected, and the corresponding improvement measures are given according to the impact results. It is found that the strain of the frame truss structure is the smallest when the fragments impacts on the front side, but it may lead to the fracture of the frame truss on the back side, resulting in secondary fragments splashing. When impacting in different postures, the edge impact is the most dangerous. Although it penetrates the skin, it is very close to the failure value.