ORIGINAL_ARTICLE
Seismic Behavior of Prefabricated Column-Footing Connection
Results of an experimental investigation of the seismic performance of prefabricated column-footing connections are presented. Tests were conducted on six 1/4-scale prefabricated column specimens inserted into prefabricated footings in two Groups. Group-1 consisted of four specimens, which were tested under constant axial load and cyclic inelastic lateral displacements. The remaining two specimens in group-2, were subjected to cyclic inelastic lateral displacements only for comparison. Test results showed that this type of connection exhibits relatively higher ultimate strength comparable to fixed end connections, and fairly acceptable ductile behavior. Also the test results indicate the strength reduction in post-elastic state and the connection behavior as a semi-rigid joint.
https://www.ije.ir/article_71239_b668cfead7e044039dcda55bb659c824.pdf
1999-11-01
205
218
Prefabricated
Ductility
Cracking
Lateral load
Earthquake
Connection
Energy dissipation
A. A.
Tasnimi
tasnimi@modares.ac.ir
1
Structural Engineering Research Center, International Institute of Earthquake Engineering
AUTHOR
ORIGINAL_ARTICLE
Influence of Operation Conditions Upon the Dynamic Steady State Performance of Switched Reluctance Motor
In order to obtain more accurate predicted dynamic steady-state performance with shorter computation time, an available mathematical model is modified and presented. Using this modified model, performance of a typical switched reluctance motor (SRM) under a wide range of variations of operating conditions is obtained and discussed. These include variations of speed, voltage, load and switching angle. The static test characteristics of the motor are carefully measured and the measured flux-linkage data are then used to predict the steady-state performance.
https://www.ije.ir/article_71240_669dbd00e395e60b80dba4c4e97a803b.pdf
1999-11-01
219
232
Switched reluctance motor
dynamic performance
Performance Prediction Techniques
E.
Shafagh
hasnomail@ije.ir
1
Electerical Engineering, University of Tabriz
AUTHOR
Jawad.
Faiz
jfaiz@ut.ac.ir
2
Electrical and Computer Engineering, University of Tehran
AUTHOR
ORIGINAL_ARTICLE
Mathematical Programming Models for Solving Unequal-Sized Facilities Layout Problems - a Generic Search Method
This paper present unequal-sized facilities layout solutions generated by a genetic search program named LADEGA (Layout Design using a Genetic Algorithm). The generalized quadratic assignment problem requiring pre-determined distance and material flow matrices as the input data and the continuous plane model employing a dynamic distance measure and a material flow matrix are discussed. Computational results on test problems are reported as compared with those of layout solutions generated by the branch and bound algorithm, a hybrid method merging simulated annealing and local search techniques and an optimization process of an enveloped block.
https://www.ije.ir/article_71241_d1b7d0fb8f16df2d59dce18afb0e1c75.pdf
1999-11-01
233
246
Facilities Layout Problems
mathematical models
heuristics
Genetics Algorithms
Reza
Tavakkoli-Moghaddam
tavakoli@ut.ac.ir
1
Industrial Engineering, University of Tehran
AUTHOR
ORIGINAL_ARTICLE
Computer Simulation of Equidxed Eutectic Solidifiction of Metals
In the present work, the solidification process was simulated in both macroscopic and microscopic scales. Two-dimensional heat transfer equation for conduction was applied for macroscopic modeling using enthalpy formulation and finite element method. In order to decrease execution time and/or memory capacity in finite analysis, skyline mathematical technique was adapted. The microenthalpy method using kinetic equations for microstructure formation was used for microscopic modeling. This macro-micrimodelling is able to represent transient thermal field of the system, the enthalpy and solid fraction distributions, and different aspects of microstructure: grain density, size, eutectic interlamellar and dendrite arm spacings. A good agreement was found between our numerical data with some experimental results from several research sources.
https://www.ije.ir/article_71242_e90fc5c60122845d097ab5e6916aa8c5.pdf
1999-11-01
247
258
Simulation
Solidification Process
Finite element method
Microstructure Formation
Eutectic Alloy
P
Davami
1
Materials Engineering, Sharif University of Technology
AUTHOR
N
Varhraam
2
Materials Engineering, Sharif University of Technology
AUTHOR
A
Kermanpur
3
Materials Engineering, Sharif University of Technology
AUTHOR
ORIGINAL_ARTICLE
Numerical Investigation of Combined Radiation and Nutral Convention Heat Transfer in a Horizonal Annulus
Combined radiation and natural convection within the annular region of two infinitely long horizontal concentric cylinders are investigated numerically in this research. Radial and tangential radiation effects ate considered using Milne-Eddington approximation for a two-dimensional radiative transfer. The basic conservation equations are discretized with the finite volume method and SIMPLER algorithm. The result are presented through velocity vector field, streamline and isothermal plots. It is observed that radiation has significant effect on flow and temperature fields. Results of local Nusselt number prediction along the surface of the inner cylinder show that radiation suppresses the angular dependence of Nusselt number.
https://www.ije.ir/article_71243_85efcd417ad2e4bd2fb59fb58300eb2f.pdf
1999-11-01
259
270
Radiation
Laminar Natural Convection
SIMPLER
A
Sinaie
1
Mechanical Engineering, Shahid Bahonar University of Kerman
AUTHOR
S. H.
Mansouri
mansouri@alum.mit.edu
2
Mechanical Engineering, Shahid Bahonar University of Kerman
AUTHOR
M.
Djavidi
hasnomail@ije.ir
3
Mechanical Engineering, Shahid Bahonar University of Kerman
AUTHOR
M.
Rahnama
mrah88@yahoo.com
4
, Shahid Bahonar University of Kerman
AUTHOR
ORIGINAL_ARTICLE
Machine Repair Queueing System with with Non-Reliable Service Stations And Heterogeneous Service Discipline (RESEARCH NOTE)
This investigation deals with M/M/R/N machine repair problem with R non-reliable service stations which are subjected to unpredictable breakdown. 1here is provision of an additional server to reduce backlog in the case of heavy load of failed machines. 1he permanent service stations repair the failed machines at an identical rate m and switch to faster repair rate when all service stations are busy. By using matrix geometric theory, the formulae for obtaining the optimal number of service stations is derived.
https://www.ije.ir/article_71244_b2bd932375c0b6a5a5b0bee9619d13cc.pdf
1999-11-01
271
276
Machine
Repair
Markov Queue
Non
reliable
Server Breakdown
Additional Server
Matrix Geometric
R. P.
Ghimire
hasnomail@ije.ir
1
, S. N. Multiple Campus
AUTHOR
Madhu
Jain
drmadhujain@yahoo.co.in
2
Department Of Mathematics, IIT Roorkee,Roorkee,India
AUTHOR