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Bonāb, Iran

Abazadeh B.,University of Bonab | Chakherlou T.N.,University of Tabriz | Alderliesten R.C.,Technical University of Delft
International Journal of Mechanical Sciences | Year: 2013

Two applied fatigue life improvement techniques of joints, interference fitting and bolt clamping, have been investigated comparing available experimental and finite element simulation results for Al-alloy 2024-T3 double shear lap joint specimens. Fatigue test results of interference fitted, bolt clamped and combined interference fitted-bolt clamped specimens were used to determine the effect of the different techniques on the fatigue life improvement in comparison with clearance fitted specimens. Also the fracture surfaces of the specimens were analyzed post-mortem to determine the fatigue crack initiation (and growth) locations. These locations were correlated to the applied cyclic load range. Results of the finite element analysis were used to help explain the trends observed in the experimentally obtained S-N data. Results showed that the fatigue life improvement not only changes for different techniques and magnitude of interference fit or tightening torque, but also depends on the applied cyclic load range. © 2013 Elsevier Ltd. All rights reserved. Source

Abdi-Ghaleh R.,University of Bonab | Asad M.,Shiraz University
European Physical Journal D | Year: 2015

In this paper, a proposal for designing the one-dimensional magnetophotonic crystals operating at visible wavelengths is presented. To this aim, a binary all-dielectric periodic structure is considered with quarter wavelength optical thicknesses condition. However, the Bi:YIG as a magneto-optical defect layer with two different optical thicknesses of λ 0 /2 and 4eλ0 is utilized. Using the 4 × 4 transfer matrix method the defect mode properties of the considered structures are investigated regarding the different period numbers and various magneto-optical defect layer positions. Analyzing the transmittance, Faraday rotation and absorption coefficient of these structures for the 720 nm visible light, the optimum structures are proposed for both cases of magneto-optical defect layer thicknesses. These structures may have potential applications in designing the miniaturized magneto-optical devices such as magneto-optical sensors and isolators and integrated photonic elements. ©EDP Sciences Società Italiana di Fisica Springer-Verlag 2015. Source

In this paper, we introduce a general iterative algorithm for finding the common element of the set of common fixed points of an infinite family of nonexpansive mappings, the set of solutions of systems of equilibrium problems and the set of solutions of systems of variational inequalities for two strongly monotone mappings in a real Hilbert space. Then, we prove a strong convergence theorem of the iterative sequence generated by the proposed iterative algorithm under some suitable conditions. Our results improve and extend the corresponding results announced by Colao and Marino [V. Colao and G. Marino, strong convergence for a minimization problem on points of equilibrium and common fixed points of an infinite family of nonexpansive mappings, Nonlinear Anal. (2010) 3513-3524] and many others. © 2011 Elsevier Ltd. Source

Chakherlou T.N.,University of Tabriz | Razavi M.J.,University of Tabriz | Abazadeh B.,University of Bonab
Engineering Failure Analysis | Year: 2013

In this paper, the effect of bolt clamping force on the fatigue life of bolted double shear lap joints was investigated numerically. To do so, finite element simulation results were used to illustrate the trends occurred in experimental fatigue tests showing the effect of bolt clamping on improving the fatigue life of double shear lap joints. The results show that clamping force decreases the resultant longitudinal stress at the hole edge thus the fatigue life increases compared to clearance fit specimens. In general, at higher tightening torque longer fatigue lives were achieved, however, below a certain load level the life improvement was discontinued because of fretting occurrence. Also lubricating the specimens reduces the advantages of the clamping force. © 2012 Elsevier Ltd. Source

Abazadeh B.,University of Bonab | Chakherlou T.N.,University of Tabriz | Farrahi G.H.,Sharif University of Technology | Alderliesten R.C.,Technical University of Delft
Materials and Design | Year: 2013

In this paper seven different multiaxial fatigue criteria based on stress, strain and energy were employed to estimate the fatigue lives of double shear lap joint specimens of aluminum 2024-T3 with bolt clamped and interference fitted-bolt clamped fastener holes. Detailed finite element (FE) simulations were conducted to obtain the stress and strain distributions in the joint to be used to as basic data in estimating the fatigue lives using multiaxial fatigue criteria. The estimated lives were compared with available experimental fatigue test results to investigate the capability of the criteria in predicting the fatigue lives. The results showed that the accuracy of life estimation for any criterion varies for different batches of specimens and applied load ranges. However, including the fatigue crack growth life can improve the fatigue estimation life and reduce the absolute error of multiaxial fatigue criteria. © 2012 Elsevier Ltd. Source

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