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Performance of buried gas distribution pipelines subjected to reverse fault movement
, Article Journal of Earthquake Engineering ; 2017 , Pages 1-24 ; 13632469 (ISSN) ; Rahimzadeh Rofooei, F ; Khajeh Ahmad Attari, N ; Sharif University of Technology
Abstract
In the current work, the results of full-scale laboratory testing of 114.3 and 168.3 mm in diameter steel gas distribution pipes buried at different depths and in two different soil types under a reverse fault offset of 0.6 m are presented and discussed in terms of longitudinal strain distribution, pipe deformation, and cross-section distortion. Results show that the pipe deformation and accordingly its failure mode, and soil failure planes change with increasing burial depth. It was also found that severe cross-section distortion occurs at about 2.3 times the strain limit for onset of wrinkling suggested by various guidelines. © 2017 Taylor & Francis Group, LLC
Performance of buried gas distribution pipelines subjected to reverse fault movement
, Article Journal of Earthquake Engineering ; Volume 22, Issue 6 , 2018 , Pages 1068-1091 ; 13632469 (ISSN) ; Rahimzadeh Rofooei, F ; Khajeh Ahmad Attari, N ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
In the current work, the results of full-scale laboratory testing of 114.3 and 168.3 mm in diameter steel gas distribution pipes buried at different depths and in two different soil types under a reverse fault offset of 0.6 m are presented and discussed in terms of longitudinal strain distribution, pipe deformation, and cross-section distortion. Results show that the pipe deformation and accordingly its failure mode, and soil failure planes change with increasing burial depth. It was also found that severe cross-section distortion occurs at about 2.3 times the strain limit for onset of wrinkling suggested by various guidelines. © 2018, © 2018 Taylor & Francis Group, LLC
A finite element model for tapered laminated beams incorporated with magnetorheological fluid using a layerwise model under random excitations
, Article Mechanics of Advanced Materials and Structures ; Apr , 2018 , Pages 1-8 ; 15376494 (ISSN) ; Zabihollah, A ; Behzad, M ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
Laminated composite beams with variable thickness are being widely used in many engineering applications. To enhance the dynamic behavior of structures subject to random loading, tapered laminated beams incorporated with magnetorheological (MR) fluids (MR-tapered beam) are proposed. A finite element model has been developed for random vibration analysis of MR-tapered beam based on layerwise displacement theory. The effects of thickness ratios of tapered beam, magnetic fields, statistical properties, correlation and autocorrelation on dynamic behaviors of structures have been investigated. The proposed structural element significantly enhances the dynamic response of MR-tapered beam under...
A finite element model for tapered laminated beams incorporated with magnetorheological fluid using a layerwise model under random excitations
, Article Mechanics of Advanced Materials and Structures ; Volume 27, Issue 1 , 2020 , Pages 12-19 ; Zabihollah, A ; Behzad, M ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
Laminated composite beams with variable thickness are being widely used in many engineering applications. To enhance the dynamic behavior of structures subject to random loading, tapered laminated beams incorporated with magnetorheological (MR) fluids (MR-tapered beam) are proposed. A finite element model has been developed for random vibration analysis of MR-tapered beam based on layerwise displacement theory. The effects of thickness ratios of tapered beam, magnetic fields, statistical properties, correlation and autocorrelation on dynamic behaviors of structures have been investigated. The proposed structural element significantly enhances the dynamic response of MR-tapered beam under...
High quality factor RF inductors using low loss conductor featured with skin effect suppression for standard CMOS/BiCMOS
, Article Proceedings - Electronic Components and Technology Conference, 31 May 2011 through 3 June 2011 ; June , 2011 , Pages 163-168 ; 05695503 (ISSN) ; 9781612844978 (ISBN) ; Sandoval, T ; Zhuang, Y ; Schellevis, H ; Rejaei, B ; Sharif University of Technology
2011
Abstract
Integrated on-chip inductors with high quality factors are demonstrated using a low loss artificial conductor technology. This concept is based on an artificial layered meta-material comprising a bi-layered Ni 80Fe 20/Cu superlattice. By properly tailoring the thickness ratio between the non-magnetic and magnetic metallic layers, the skin effects can be effectively suppressed within a wide frequency range, and can be tuned to a minimum at the frequency of interest up to 67 GHz. The quality factor has been increased by 41% of a 2nH inductor at 14.5GHz. The bandwidth of skin effect suppression is obtained between 10-18 GHz
The Effects of Local Buckling on Behavior of Steel Braces
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Steel Concentrically Braced Frames are common lateral load resisting frames. Poor design of this system can lead it to premature failure of braces. This failure may be due to non-elastic buckling of brace members or their connections. Design Codes divide Concentrically Braced frames into two groups: Ordinary Concentrically Braced Frames and Special Concentrically Braced Frames and for each, specific limitations have been determined for width to thickness ration and slenderness. Many of these limitation have been obtained on the basis of experimental tests. In this thesis steel braces behavior under cyclic loading is studied. For parametric investigation, Finite Element Method is used. Abaqus...
New visions in experimental investigations of a supersonic under-expanded jet into a high subsonic crossflow
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 224, Issue 10 , 2010 , Pages 1069-1080 ; 09544100 (ISSN) ; Soltani, M. R ; Taeibi Rahni, M ; Sharif University of Technology
2010
Abstract
A series of experiments was performed to investigate the interaction of an under-expanded axisymmetric supersonic jet exhausted from a flat plate with a high subsonic crossflow. The goal was to study the effect of boundary layer thickness (δ) and jet to freestream dynamic pressure ratio (J) on flow field pressure distributions. The resulting measurements upstream of the jet showed that with increasing boundary layer thickness, the magnitude of the pressure coefficient decreases, whereas downstream of the jet, the recovery of the back-pressure moved closer to the nozzle exit. Flow field measurements indicated that with increasing boundary layer thickness, the jet plume dissipation rate...
On the static and dynamic stability of thin beam conveying fluid
, Article Meccanica ; Volume 54, Issue 11-12 , 2019 , Pages 1847-1868 ; 00256455 (ISSN) ; Abtahi, H ; Firouz Abadi, R. D ; Sharif University of Technology
Springer Netherlands
2019
Abstract
In this paper, numerical investigation of the statical and dynamical stability of aligned and misaligned viscoelastic cantilevered beam is performed with a terminal nozzle in the presence of gravity in two cases: (1) effect of fluid velocity on the flutter boundary of beam conveying fluid and (2) effect of gravity on the buckling boundary of beam conveying fluid. The beam is assumed to have a large width-to-thickness ratio, so the out-of-plane bending rigidity is far higher than the in-plane bending and torsional rigidities. Gravity vector is considered in the vertical direction. Thus, deflection of the beam because of the gravity effect couples the in-plane bending and torsional equations....
Effect of mode shape switching on the loss factor of sandwich cylinders
, Article AIAA Journal ; Volume 58, Issue 8 , August , 2020 , Pages 3577-3592 ; Asgari, M ; Haddadpour, H ; Sharif University of Technology
American Institute of Aeronautics and Astronautics Inc
2020
Abstract
Damping characteristics of three-layered sandwich cylindrical shells with the focus on mode switching phenomenon are investigated in the present study. All layers of the sandwich cylinder are formulated based on the first-order shear deformation theory. Considering the von Karman strain displacement relations, the nonlinear equations of motion are derived through Hamilton’s principle. By separating the displacement components into previbration and vibration states and substituting in the obtained nonlinear equations of motion, the previbration equilibrium equations and vibration equations of motion are obtained. The acquired equations are solved by applying the generalized differential...
Nonlinear cylindrical bending analysis of shear deformable functionally graded plates under different loadings using analytical methods
, Article International Journal of Mechanical Sciences ; Volume 50, Issue 12 , 2008 , Pages 1650-1657 ; 00207403 (ISSN) ; Haddadpour, H ; Sharif University of Technology
2008
Abstract
An exact solution is presented for the nonlinear cylindrical bending and postbuckling of shear deformable functionally graded plates in this paper. A simple power law function and the Mori-Tanaka scheme are used to model the through-the-thickness continuous gradual variation of the material properties. The von Karman nonlinear strains are used and then the nonlinear equilibrium equations and the relevant boundary conditions are obtained using Hamilton's principle. The Navier equations are reduced to a linear ordinary differential equation for transverse deflection with nonlinear boundary conditions, which can be solved by exact methods. Finally, by solving some numeral examples for simply...
Design, modeling and optimization of a piezoelectric pressure sensor based on thin-film PZT diaphragm contain of nanocrystalline powders
, Article 2009 6th International Symposium on Mechatronics and its Applications, ISMA 2009, Sharjah, 23 March 2009 through 26 March 2009 ; 2009 ; 9781424434817 (ISBN) ; Sheikhi, M. H ; Torkian, S ; Barzegar, A ; Masumi, E ; Mohammadi, S ; Sharif University of Technology
2009
Abstract
In this paper fabrication of a 0-3 ceramic/ceramic composite lead zirconate titanate, Pb(Zr0.52Ti0.48)O3 thin film has been presented and then a pressure sensor based on multilayer thin-film PZT diaphragm contain of Lead Zirconate Titanate nanocrystalline powders was designed, modeled and optimized. This multilayer diaphragm in general acts as sensor or actuator. ANSYS was used for simulation of diaphragm. Dynamics characteristics of this multilayer diaphragm have been investigated. By this simulation the effective parameters of the multilayer PZT diaphragm for improving the performance of a pressure sensor in different ranges of pressure are optimized. The optimized thickness ratio of PZT...