Browsing by Author "Ignatovich, S.R."

Now showing 1 - 8 of 8

Computer aided optical method for aircraft's components fatigue life estimation
(2008-09) Ignatovich, S.R.; Karuskevich, M.V.; Maslak, T.P.
The results of numerous tests show that quantitative estimation of accumulated fatigue damage may effectively be conducted by computer-aided optical analysis of the surface state. The method may be applied for alclad alluminium alloys which are used for modern aircraft skin manufacturing. The developed optical system and its software allow to determine the density of the areas with slip bands (damage parameter D), and a set of surface pattern fractal dimensions. These parameters allow to indicate more dangerous points of aircraft structures, predict fatigue crack under full scale test of aircraft structures as well as estimate residual service life.
Evolution of the deformation relief on the surface of a clad aluminum alloy at random cyclic loads
(IPC Science and Technology Press, 2017) Ignatovich, S.R.; Karuskevich, M.V.; Yutskevych, S.S.
The deformation relief was revealed to be formed and evolved on the surface of a cladding layer of a D16AT aluminum alloy under random cyclic loading. The surface saturation, roughness, and microplastic deformation are found to be quantitative estimates of the deformation relief and damage levels. Experimental deformation relief characteristics-load cycle number relations are similar and can be employed for predicting the fatigue crack initiation in aircraft structure elements.
Fatigue cracks growth features in aluminum alloy D16AT
(2016) Ignatovich, S.R.; Krasnopolskii, V.S.
This paper investigates the description of the fatigue cracks growth in sheet aluminum alloy D16AT by exponential dependence. The results show that the propagation of all investigated fatigue cracks can be satisfactorily described by this dependence with grate values of the determination coefficient.
Fatigue damage and sensor development for aircraft structural health monitoring
(Elsevier Science Publishing Company, Inc., 2013-06) Ignatovich, S.R.; Menou, A.; Karuskevich, M.V.; Maruschak, P.O.
It was shown by tests conducted at the National Aviation University (Kiev, Ukraine) that fatigue damage of metal structures may be estimated by sensors with the surface relief pattern to indicate the accumulated fatigue damage. The nature of the deformation relief has been investigated by the light, scan and transmission microscopy, as well as by a new nano-interferometer, developed at the National Aviation University. Fractal analysis of the surface patterns based on box-counting method has proved the efficiency of fractal geometry application for additional quantitative description of such surface structures. The evolution of deformation relief parameters on the sensors surface is determined by the process of the sensor and construction fatigue damage accumulation.
Influence of deformation process in material at multiple cracking and fragmentation of nanocoating
(Elsevier Science Publishing Company, Inc., 2012-01) Maruschak, P.O.; Panin, S.V.; Ignatovich, S.R.; Zakiev, I.M.; Konovalenko, I.V.; Lytvynenko, I.V.; Sergeev, V.P.
Strain localisation in the heat resistant nanocoated steel at the stage of cracks nucleation, coalescence, and fragmentation of the nanocoating is investigated experimentally. Regularities in the self-organisation of plastic yielding processes and their relation to the deformation relief geometry are established.
Monitoring of the fatigue of D16АТ alloy according to the characteristics of deformation surface pattern
(Springer Science+Business Media, Inc., 2012) Ignatovich, S.R.; Yutskevich, S.S.
It is shown that the deformation pattern is formed under cyclic loads and develops on the surface of the cladding layer of a structural aluminum alloy. The quantitative parameters of the deformation pattern, namely, the saturation, roughness, and plastic strains on the surface, serve as indicators of damage to the material. The experimental dependences of the analyzed parameters on the operating time (number of loading cycles) can be used for the creation of new methods aimed at the prediction of the limit state of structural elements of the aircraft structures.
Multi-purpose fatigue sensor
(Gruppo Italiano Frattura, 2016-10) Karuskevich, M.V.; Ignatovich, S.R.; Maslak, Т.P.; Menou, A.; Maruschak, P.О.; Panin, S.V.; Berto, F.
The paper describes the key principles and results of preliminary experiments aimed at the development of new technique for the fatigue life prediction under conditions of biaxial cyclic tension. The foundations of the method were developed early by the numerous tests with monitoring the process of surface deformation relief formation, which is proved to be an indicator of accumulated fatigue damage under uniaxial fatigue. The employed phenomenon was early applied for the development of a family of uniaxial loading fatigue sensors. The formation of strain induced relief has been recently taken into consideration as a part of damage accumulation criteria under biaxial fatigue as well. The home-made testing machine has been designed to implement combined bending and torsion loading that simulates loads experienced by an aircraft wing skin. The experimental evidences on formation and evolution of the deformation relief revealed under conditions of combined loading, supports the proposed concept of biaxial fatigue sensor. The characteristic informative parameters for defect detection to be used in fatigue sensors have been established. Their development is interpreted in terms of scale levels of deformation and fracture. Damage accumulation of the sensor’s surface tends to exhibit the self-organization nature. It is accompanied by formation of "folded" strain-induced relief on the surface. The mechanisms of damage accumulation under cyclic deformation were analyzed with the use of the multiscale approach.
The evaluation of the crack-like damage parameter of blades at the vibroacoustical diagnosis of the gas-turbine engines
(2012-05) Ignatovich, S.R.; Bouraou, N.
This work is devoted to vibroacoustical condition monitoring of the gas-turbine engines (GTE) blades and diagnosis of the crack-like damages at the steady-state and non-steady-state modes of GTE. For detection of the mentioned damages we proposed the application and further development of the low-frequency vibroacoustical diagnostic methods which use vibrating and acoustical noise as diagnostic information. The following amplitude dimensionless characteristics are used as fault features: probability factor, peak factor and factor of background. The evaluation of the crack-like damage of the blades is carried out at the steady-state and non-steady-state modes by using the generalized likelihood method. The statistical quality of the received estimations is investigated.