@article { author = {Ahmadi, Hamid Reza and Hamidi Jamnani, Hamed and Ghodrati Amiri, GH.R.}, title = {The Effect of Analysis Methods on the Response of Steel Dual-System Frame Buildings for Seismic Retrofitting}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {317-331}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In the present paper, the focus is on the evaluation of steel dual-system frame buildings using four main types of structural analysis (Linear Static, Linear Dynamic, Nonlinear Static and Nonlinear Dynamic Analyses) with regard to "Seismic Rehabilitation Code for Existing Buildings in Iran" (based on FEMA 273 and 356) where the first two authors of the article tend to follow the previous work (Section 2). The difference of the results taken from these four types of analyses and also seismic performance of the dual-system buildings will be studied in both linear and nonlinear treatments. Three 2D models which include 3 common dual-system buildings (5,10 and 15-story) have been chosen and designed subjected to earthquake based on the Standard No. 2800 of Iran (3rd revision). Then, the 2D models have been analyzed and controlled according to “Seismic Rehabilitation Code for Existing Buildings”. The selected rehabilitation goal for this research is Fair (Controlling Life Safety and Collapse Prevention in two hazard levels derived from PSHA analysis). Based on the research results, the main role of lateral load-bearing is on bracing members. The linear analysis of bracing members evaluation, has a low accuracy, in evaluation of columns the results derived from linear static analysis shows more accuracy than linear dynamic and nonlinear static analyses. Also, the accuracy of nonlinear static analysis decreases when the number of stories increases.}, keywords = {Seismic Retrofitting,Steel Dual,System Frame Building,Linear analysis,Nonlinear analysis,Seismic Hazard Analysis}, url = {https://www.ije.ir/article_71810.html}, eprint = {https://www.ije.ir/article_71810_b1e38224f7188012fcc1c10a16721fd9.pdf} } @article { author = {Rezaei, Mohammad Javad and Zarrati, A.R. and B. Mashahir, Mohammad and Zokaei, Masood}, title = {Effect of Collars and Bars in Reducing the Local Scour Around Cylindrical Bridge Piers}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {333-342}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In the present work, the efficiency of single and double collar in reducing scour rate and depth around cylindrical bridge piers was studied experimentally. In order to reduce the strength of wake vortices, different numbers of bars were also installed at the downstream face of the pier in combination with a single collar. The best result was achieved for double collar when the collars were installed at the streambed level and one pier diameter below bed level. With this arrangement the lower collar was not undermined after 80 hours of experiment, showing about 56 % reduction in scouring compared with an unprotected pier. It was also shown that by using collars, the rate of scouring decreased considerably. Though installation of bars did not significantly reduce the maximum depth of scour, it postponed the beginning of scouring at the upstream face of the pier.}, keywords = {bridge pier,bar,collar,Scouring,Time Development}, url = {https://www.ije.ir/article_71812.html}, eprint = {https://www.ije.ir/article_71812_87cf1948a0840f1cb31b083220d3f078.pdf} } @article { author = {Alavi, Erfan and Nateghi, F.}, title = {Non-Linear Behavior and Shear Strength of Diagonally Stiffened Steel Plate Shear Walls}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {343-356}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this study, non-linear behavior of diagonally stiffened steel plate shear walls as a seismic resisting system has been investigated, and theoretical formulas for estimating shear strength capacity of the system have been proposed. Several validated analytical finite element models of steel shear walls with various stiffener dimensions are generated to verify and compare the analytical and theoretical outcomes. Non-linear transient analysis under monotonic loading are carried out and the pushover curves of the models are obtained. It is observed that the diagonal stiffeners have been able to reduce the buckling effects of the infill steel plate, and they have increased the elastic shear buckling strength and the ultimate shear capacity of the system in comparison with the un-stiffened thin steel plate shear walls, and there are good agreements between the propounded theoretical method and the analytical results.}, keywords = {Steel Plate Shear Walls,Diagonal Stiffeners,Shear strength,Non,Linear analysis}, url = {https://www.ije.ir/article_71813.html}, eprint = {https://www.ije.ir/article_71813_4b5ec9f7d6f264e0e0f4aee6934f6c77.pdf} } @article { author = {Siadatan, A.R. and Afjei, E.}, title = {A Novel Two Phase Hybrid Switched Reluctance Motor/Field-Assisted Generator: Concept, Simulation, and Experimental Confirmation}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {357-368}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The switched reluctance motor is a simple and robust machine, which has found application over a wide power and speed ranges in different shapes and geometries. This paper introduces a new configuration for a two phase unidirectional switched reluctance motor/field assisted generator. The proposed novel motor/generator consists of two magnetically independent stator and rotor sets (layers), where each stator set includes four salient poles with windings wrapped around them, while the rotor comprises of two salient poles with different arc lengths and no windings. There is a stationary reel, which has the field coils wrapped around it and is placed between the two-stator sets. In the motor mode of operation the two sets are connected independently. In this connection the stator poles in each layer can have both North and South Pole configurations. In the generator mode, the stator poles in one set can have either north or South Pole configuration while the stator poles in the other set (layer) have the opposite pole arrangements. In this format, the developed magnetic field from the stator poles travels to the rotor then to the rotor shaft and finally completes its path via the motor/generator housing. To evaluate the motor performance, two types of analysis, namely, the numerical technique and the experimental study have been utilized. In the numerical analysis, the finite element analysis is employed, where as in the experimental study, a proto-type motor has been built and tested.}, keywords = {Switched reluctance motor,Reluctance Motor/Generator,Hybrid Brushless Motor}, url = {https://www.ije.ir/article_71815.html}, eprint = {https://www.ije.ir/article_71815_72a985287b2f05b226fd81080d013333.pdf} } @article { author = {Sadegian, M.H. and Abbaspour, Z. and Moayed, Mohammad Hadi}, title = {Study of Pitting Corrosion Inhibition of Mild Steel by Nitrite in Concrete Pore Solution by Polarization and Zero Resistance Ammetery (ZRA) Techniques (RESEARCH NOTE)}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {369-380}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {A research on the corrosion inhibition of mild steel pitting corrosion in concrete pore solution by sodium nitrite was carried out by employing potentiodynamic, potentiostatic polarization and zero resistance ammetery (ZRA) techniques. Passivity breakdown potential was decreased from the transpassive potential of 700 mV at the absence of chloride to a value of -50 mV when just 0.01M NaCl was added to the test solution and further a decrease to -350 mV was recorded when the concentration of chloride was increased to 0.5M. Addition of NaNO2 into the saturated Ca(OH)2 solution containing 0.5M NaCl considerably shifted the pitting potential towards noble values. Similar results of inhibitive effect of nitrite were obtained from couple potential and current measurement between two nominal identical electrodes through ZRA establishment. In the test solution containing NaNO2, continuous increasing of the corrosion potential towards noble values and simultaneous decrease in couple current density towards zero proved the stability and improvement of the passive film. Whereas, continuous decrease in couple potential accompanied with sharp increase in couple current density with a stable value of 3µA/cm2 at the absence of NaNO2 demonstrated the occurrence of pitting corrosion.}, keywords = {Concrete Pore Solution,Zero Resistance Ammetery (ZRA),Pitting Corrosion,Sodium Nitrite}, url = {https://www.ije.ir/article_71818.html}, eprint = {https://www.ije.ir/article_71818_33ec0c4e6e141db1bd7826dd4602c5f8.pdf} } @article { author = {Yazdani, B. and Nikzad, L. and Vaezi, M.R.}, title = {Synthesise of CoFe2O4-Polyaniline Nanocomposite and Evaluation of its Magnetic Properties}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {381-386}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Particles of Cobalt ferrite, CoFe2O4-, were coated with polyaniline (PANI) sulphate and phosphate during in-situ polymerization of aniline in an aqueous solution of sulfuric and phosphoric acid. The PANI-ferrite composites were characterized by Fourier transform infrared (FTIR) spectroscopy. Structures and morphology of products were studied by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The crystallite size calculated by XRD was 16.65 nm. Magnetic measurement shows that CoFe2O4- and nanocomposite exhibit ferromagnetic behavior. The saturation magnetization, Ms, remanent magnetization Mr and coersivity Hc for PANI sulphate/ CoFe2O4- nanocomposite were 40 emu/g, 20 emu/g and 301 Oe respectively. The same variables for PANI phosphate/CoFe2O4- nanocomposite were 12 emu/g, 28 emu/g and 333 Oe respectively.}, keywords = {Nanocomposite,Polyaniline,Ferrite,Magnetic properties}, url = {https://www.ije.ir/article_71820.html}, eprint = {https://www.ije.ir/article_71820_e29802cbc4dffd7d79bb4bdc7f6b0a8a.pdf} } @article { author = {Mahmoodabadi, Mohammad Javad and baradaran, gholam hosain}, title = {Optimal Pareto Parametric Analysis of Two Dimensional Steady-State Heat Conduction Problems by MLPG Method}, journal = {International Journal of Engineering}, volume = {22}, number = {4}, pages = {387-406}, year = {2009}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Numerical solutions obtained by the Meshless Local Petrov-Galerkin (MLPG) method are presented for two dimensional steady-state heat conduction problems. The MLPG method is a truly meshless approach, and neither the nodal connectivity nor the background mesh is required for solving the initial-boundary-value problem. The penalty method is adopted to efficiently enforce the essential boundary conditions, the moving least squares approximation is used for interpolation schemes and the Heaviside step function is chosen for test function. As the accuracy and runtime will depend on definition radiuses of the moving least squares approximation and the Heaviside step function; therefore, a genetic algorithm is carried out to determine the optimal values for these radiuses. The results show that the present method is very promising in solving engineering two dimensional steady-state heat conduction problems.}, keywords = {Meshless Local Petrov,Galerkin,Moving Least Squares,Heaviside Step Function,Heat Conduction,optimization,Genetic Algorithm}, url = {https://www.ije.ir/article_71821.html}, eprint = {https://www.ije.ir/article_71821_aa60be481f3c92efd2b94901f9ae8717.pdf} }