Authors: E.S. Esakkiraj, S. Anish, V. Anish
Abstract: The cold of this cardboard is to abstraction and analyze the amount accustomed accommodation and weight accumulation of blended aircraft (Aluminium Silicon Carbide) addition with that of Aluminium wing and appropriately access the acceptable aircraft addition of minimum weight accomplished of address a accustomed changeless amount after failure. And also this paper presents a model and a static analysis of the aircraft wing, using the finite element software ANSYS. The geometry was created in CATIA V5 R18 and imported. The static and model analysis are carried out in analysis software ANSYS. The result of from the static analysis refers to the total deformation, equivalent stress, shear stress and shear intensity on the skin of the aircraft wing. The model analysis will be carried out to find out the first six modes of vibrations and the different mode shape in which wing can deform without the application of load. Compared to the conventional Aluminium wing, the hybridized composite wing experience far lower stresses and the aircraft wing weight nearly 40% and 50% lower stress.
367
Authors: S. Suresh Kumar, V. Veeraraghavan, M. Vimalesh, Sanjay B. Bharadwaj
Abstract: Structural failure of aircraft wings due to nucleation and propagation of cracks is one of the main reasons for failure of aged aircrafts. Reported studies on aircraft failures indicate that the main cause of wing failure is due to fatigue cracks which nucleate from the wing root region. Thus, determination of residual life of the cracked wing structure using fracture mechanics approach becomes important. In the present work an attempt has been made to estimate the SIF of single and multiple cracks in an aircraft wing subjected to lift force. Crack depth ratios ranging between 0.1 and 0.4 and aspect ratios of 0.6 and 1.0 have been considered. Single and multiple cracks are introduced at the wing rib region and the lift force is applied at the bottom surface of the wing. Geometric correction factor (Y) is estimated with the additional consideration of mode II and mode III fracture. The effect of crack depth ratio and number of cracks on SIF is determined. Non symmetric SIF distribution is observed with increase of crack depth ratio. It is also noted that SIF values are always higher at the crack surface region compared to crack middle region irrespective of crack depth ratio.
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Authors: Syed Mohammed Aminuddin Aftab, P. Srinivasa Murthy
Abstract: Flow over the ONERA M6 wing with vortex generators using more accurate higher order numerical schemes is studied using computational methods. In this paper, the effect of delta vortex generator orientation on the wing and its implication on wing performance is computed more accurately using second order upwinding scheme. Turbulence modeling used is k-omega sst. It has been found that numerical results are comparable and close to the experiment. The analysis results show that the co-rotating clockwise position of vortex generators is more effective than co-rotating (anticlockwise) or counter rotating position. The vortex generators have been found to control the boundary layer separation and give improvement in lift at high angle of attack.
79
Authors: Da Zhao Yu, Wei Han, Shu Yan Liu
Abstract: Based on initial discontinuity state (IDS) of material, this paper presents a preliminary analytical model which was developed to evaluate the effect of exfoliation corrosion on the residual fatigue life of upper wing skins. A life prediction was then carried out using constant amplitude compression dominated loading for various exfoliation corrosion levels by AFGROW, and the prediction agreed reasonably with the available test data. The result suggest that exfoliation can be treated as a process zone located initially at a surface, and then at the base of an evolving general stress concentration representing the loss of material in the exfoliation region. The major effect of the exfoliation corrosion on fatigue life is to cause a dramatic reduction in life with small corrosion depths, and most of the fatigue effect is associated with the introduction of small pits, rather than more general stress concentration associated with the bulk of the exfoliation attack. But the effect of pit on fatigue life is gradually reduced with increasing pit size. A pit with a constant depth can be applied to the model described in this paper for long exposure structure. A preliminary recommendation for the pit depth is about 0.3mm for LY12CZ.
19
Authors: Irina Trendafilova
Abstract: This work investigates the use of two different vibration-based methods for health
monitoring of aircraft wings. A finite element model of a simplified wing is used to model and predict the vibration response of an aircraft wing in an intact condition and in the presence of different types and levels of damage. Two main types of damage are considered- cracks and distributed damage. This study first explores the sensitivity of the lower modal frequencies to different damage levels of the studied types. Then the employment of the frequency response functions subjected to principal components analysis is discussed. This is an early model-based study which is intended to establish if the considered procedures can be used as damage detection tools.
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