Procena veka i integritet vazduhoplovnih konstrukcija od aluminijumskih legura AA2024 i AA7075 u korozionom okruženju
Assessment of the life and integrity of aircraft structures made of aluminium alloys AA2024 nad AA7075 in a corrosion environment
Докторанд
Petrović, Zoran C.Ментор
Sedmak, AleksandarЧланови комисије
Radaković, ZoranĐukić, Miloš
Grbović, Aleksandar
Burzić, Zijah
Метаподаци
Приказ свих података о дисертацијиСажетак
Opšte je poznato da su elementi strukture vazduhoplova, izrađeni od aluminijumskih
legura povišene i visoke čvrstoće, u ekspolataciji dominantno izloženi delovanju promenljivog
opterećenja, u uslovima delovanja koroziono aktivne radne sredine, a problem se dodatno
usložnjava mogućim i realno verovatnim prisustvom grešaka tipa prsline.
Na osnovu rezultata ispitivanja, analiziran je uticaj eksploatacionih uslova na stanje
osnovnog materijala vazduhoplovne konstrukcije predviđene za rad u uslovima delovanja
promenljivog opterećenja, a radi procene integriteta i preostalog veka konstrukcije.
Za potrebe istraživanja primenjene su numeričke i eksperimentalne metode, pri čemu je
istražen uticaj delovanja promenljivog opterećenja na strukturne elemente vazduhoplova,
izrađene od aluminijumskih legura povišene i visoke čvrstoće, 2024-T351 i 7075-T651, sa
prisustvom grešaka tipa prsline, a u uslovima delovanja koroziono aktivne radne sredine.
Istraživanje uticaja korozije na rast prsline i lom st...ruktura izrađenih od legura
aluminijuma 2024-T351 i 7075-T651 provedeno je kroz četiri faze: (1) Ispitivanje uticaja
korozije na mehanička svojstva legura aluminijuma 2024-T351 i 7075-T651 – Statička zatezna
ispitivanja; (2) Ispitivanje uticaja korozije na parametre mehanike loma legura aluminijuma
2024-T351 i 7075-T651 – Dinamička zatezna ispitivanja; (3) Simulacija rasta zamorne prsline
u leguri aluminijuma 2024-T351 – Procena broja ciklusa opterećenja do loma i poređenje sa
rezultatima dobijenim eksperimentalnom analizom; (4) Procena broja ciklusa opterećenja do
loma okvira trupa aviona, u zavisnosti od dužine inicijalne prsline, opsega napona i vremena
izloženosti predmetne strukture dejstvu korozione sredine.
It is generally known that the elements of the aircraft structure, made of aluminum
alloys of increased-strength and high-strength, are dominantly exposed to the action of variable
load during operation, under the conditions of action of a corrosively active working
environment, and the problem is further complicated by the possible and realistically probable
presence of cracks.
Based on the test results, the impact of operational conditions on the state of the basic
material of the aircraft structure intended for operation under variable load conditions was
analyzed, in order to assess the integrity and remaining life of the structure.
Numerical and experimental methods were applied for the purposes of the research,
where the influence of the action of variable load on the structural elements of the aircraft,
made of aluminum alloys of elevated and high strength, 2024-T351 and 7075-T651, with the
presence of cracks under the conditions of the corrosively active working environment was...
investigated.
The investigation of the effect of corrosion on crack growth and fracture of structures
made of aluminum alloys 2024-T351 and 7075-T651 was carried out through four phases: (1)
Testing the influence of corrosion on the mechanical properties of aluminum alloys 2024-T351
and 7075-T651 – Static tensile tests: (2) Testing the influence of corrosion on fracture
mechanics parameters of aluminum alloys 2024-T351 and 7075-T651 – Dynamic tensile tests:
(3) Simulation of fatigue crack growth in aluminium alloy 2024-T351 – Estimation of the number
of load cycles to fracture and comparison with the results obtained by experimental analysis: (4)
Assessment of the number of load cycles until the breakdown of the aircraft fuselage frame,
depending on the length of the initial crack, the stress range and the time of exposure of the
structure in question to the effect of the corrosive environment.