RESIDUAL FATIGUE LIFE ESTIMATION OF CRACKED AIRCRAFT STRUCTURAL COMPONENTS UNDER LOAD SPECTRUM
This work deals with fatigue behaviour of cracked aircraft structural components under cyclic loads of constant amplitudes and load spectrum. This investigation is focused on developing efficient and reliable computational methods for fatigue life estimation of cracked aircraft lugs under cyclic loads of constant amplitude and load spectrum. For cr...
By Katarina Maksimovic, Slobodanka Boljanovic, Mina Djuric, Ivana Vasovic Maksimovic, Mirko Maksimovic
ELECTROHYDRODYNAMIC THERMAL INSTABILITY IN A WALTERS’ (MODEL B') ROTATING NANOFLUID SATURATING A POROUS MEDIUM
The onset of thermal instability in a dielectric rotating nanofluid layer saturating a porous medium with vertical AC electric field is investigated by employing Darcy model for porous medium. The rheology of the nanofluid is described by Walters’ (model B’) for calculating the shear stresses from the velocity gradients. The employed mo...
By Gian C. Rana, Poonam Gautam, Hemlata Saxena
MODELING OF DAMAGED CONCRETE USING INITIAL DEGRADATION PARAMETER
A stress-strain history in the material of real concrete structures is usually unknown. An effect of concrete degradation is analyzed to describe how the initial degradation parameter can describe the stress-strain history. The idea is to introduce the initial damage of the structure by the degradation parameter to calculate the internal variables ...
By Dragan Rakić, Vladimir Dunić, Miroslav Živković, Nenad Grujović, Dejan Divac
NUMERICAL STUDY ON HEAT TRANSFER IN MULTILAYERED STRUCTURES OF MAIN GEOMETRIC FORMS MADE OF DIFFERENT MATERIALS
The article proposed a general research scheme of heat transfer process in multilayer constructions for three basic geometric forms in order to simulate fire distribution. The scheme is based on linear differential equations, the Fourier method and the modified method of Eigen functions. The work considers five different layers’ design and do...
By Roman M. Tatsiy, Oleg Yu Pazen, Sergiy Ya. Vovk, Lubomyr Ya. Ropyak, Tetiana O. Pryhorovska
OSCILLATIONS OF MULTILAYER VISCOELASTIC COMPOSITE TOROIDAL PIPES
This article discusses a method for calculating the dynamic characteristics of thin-walled viscoelastic composite pipes made by continuous winding under the influence of internal hydrodynamic pressures. The solution is based on an approximate energy method based on the instant theory of shells and the second-order Lagrange equation. Initial technol...
By Muhsin Kh. Muhsin Kh., Ismail I. Safarov, Mirziyod Mirsaidov
VISCOSITY VARIATION EFFECT ON THE MAGNETIC FLUID LUBRICATION OF A SHORT BEARING
The performance of a magnetic fluid based short bearing is examined with the effect of viscosity variation. The pressure temperature relation of Tipei (1962) concerning viscosity variation is adopted here. The Neuringer-Rosensweig’s model has been considered for the magnetic fluid flow. The related modified Reynolds type equation is solved fo...
By Jimit R. Patel, Gunamani Deheri
Aerodynamic performances improvement of NACA 4415 profile by passive flow control using vortex generators
Improvement of the airfoil NACA 4415 aerodynamic performances by flow control using a passive technique was achieved in this study. Gothic-shaped vortex generators were added at the profile upper surface. Vortex Generators (VG) were used to avoid boundary layer separation at the profile trailing edge, thus reducing the drag force and improving aero...
By Hocine Hares, Ghazali Mebarki, Mourad Brioua, Mahieddine Naoun
Three dimensional boundary layer flow of water based coupled stress nanofluid over a bidirectional linear stretching sheet in the presence of heat source, thermal radiation and chemical reaction
The present investigation represents a study on the effects of heat and mass transfer flow in the presence of couple stress coefficient, heat source parameter, radiation parameter, chemical reaction parameter and Schmidt number using nanofluids over a stretching sheet. The governing partial differential equations are reduced to ordinary differentia...
By Meruva Parvathi, Appikatla Leela Ratnam, Malaraju Chengal Raju
Computational Analysis of Hip Implant Surfaces
During the total or partial hip replacement procedure, a damaged part of the hip joint is replaced with an artificial one. Both types of procedures include removal and replacement of the femoral head. After the femoral head is removed, an implant is inserted into the hollow femur. When the healing process starts, the newly formed bone interlocks wi...
By Aleksandra Vulovic, Nenad Filipovic
The Effects of Buoyancy Force on the Irreversibility of Three-Dimensional Step Flow in an Inclined Duct
This research deals with the study of the irreversibility of three-dimensional mixed convection flow in an inclined duct with step. To reach this goal, an analysis of entropy generation is carried out according to the second law of thermodynamics. The effects of buoyancy force on the flow irreversibility are analyzed with all details. The results s...
By Meysam Atashafrooz, Tahereh Asadi