Multiple cold expansion holes are widely used in connection areas of aircraft structures, order to achieve uniform load transfer the skin or parts. Split sleeve (SSCE) is enhance fatigue life fastener by applying compressive residual stresses around holes. In this study, finite element method (FEM) was research distribution and variation along hole edges 7075AA single-hole multi-hole (CE) specimens. Full-field strain measurements specimens were performed using two-dimensional digital image...

The atmospheric corrosion of epoxy prime coated aluminum alloy 7075-T6 exposed for 7, 12 and 20 years was investigated. remaining thicknesses coatings macroscopically intact coating areas followed a normal distribution decreased linearly. EIS results demonstrated that the resistance with exposure time. After exposure, had lost its protection as cracks existed within exfoliation occurred on substrate. substrate sensitive to through metallographic TEM analysis. products were mainly hydroxides...

In this paper, by establishing a fragmented field of prefabricated fragment warhead and simulating the intersection aircraft under dynamic conditions, determination distribution vulnerable parts specific is realized. On basis, structural characteristic test pieces were tested with high-velocity impact experiments based on two-stage light-gas gun. Based FEM-SPH self-adaptive method, numerical simulation model high reduction degree was established. Combined experimental results, damage mode...

Aircraft are subjected to extreme weather conditions in coastal areas. This study reports long-term atmospheric exposure tests carried out on an epoxy primer-coated aluminum alloy a environment for 7, 12, and 20 years. The micromorphology characteristics of the section surface, products corrosion, electrochemical impedance, molecular structure coated specimens were examined through spectrophotometer, scanning electron microscopy (SEM), atomic force (AFM), X-ray diffraction (XRD), impedance...

To investigate the effect of alternate corrosion and fatigue on crack growth characterization 2024-T4 aluminum alloy, pure test, “corrosion + fatigue” test (commonly known as pre-corrosion fatigue), “fatigue alternating single-sided notched specimen alloy were carried out. The life is longer than that when time same. And more times alternating, will be. This mainly because rate change suddenly, which have a certain hysteresis growth. fracture morphology characteristics examined by scanning...

Advanced crack monitoring technique is the cornerstone of aircraft structural health monitoring. To achieve real-time metal structures in course service, a new method proposed based on Cu coating sensor and electrical potential difference principle. Firstly, insulation treatment process was used to prepare dielectric layer substrate, such as an anodizing 2A12-T4 aluminum alloy then deposited structure fatigue critical parts by pulsed bias arc ion plating technology. Secondly, damage...

The recent patents on corrosion resistant coatings were reviewed in this paper.The materials of components, e.g., metals and alloys, ceramics, polymers as well composite materials, developed for environmental, economic other concerns discussed.In addition, the novel methods forming coatings, including powder floating by vibration precursor gas, some widely employed industrial applications also included to provide useful information colleagues.

A two-stage light gas gun was used to conduct a high-velocity impact test on the aircraft’s typical composite/metal connecting structure (CFRP/AL). The battle damage simulations for CFRP/AL were carried out under different intersection conditions. Then, morphology and mechanism of prefabricated spherical fragments structures, dynamic process hyper-velocity impact, formation debris clouds secondary component structures investigated. Next, based X-ray computerized tomography (CT), mode areas...

Particulate fouling is a common in heat exchange equipment, it causes tube corrosion and increases flow resistance. the hidden danger of equipment requires high treatment costs. In this paper, novel Ni−P−TiO2 composite coating prepared on 316 stainless steel using electroless plating inhibition characteristics are studied dynamic monitoring experimental system. The results show that thermal resistance obviously lower than under same working conditions. With increase cooling water velocity...

Abstract The investigation of fatigue crack propagation and fracture mechanisms in high-thickness metal plates holds pivotal importance the advancement a three-dimensional damage tolerance assessment methodology. This research also bears significant implications for ensuring safe operation large-scale mechanical equipment. In this study, we examine influence specimen thickness on evolution shapes an aluminum alloy. Fatigue growth tests were conducted single-edge notch tension specimens to...