Hadi E.,Abadan Institute of Technology
Composites: Mechanics, Computations, Applications | Year: 2014
The problem of stress intensity factor (SIF) investigation for radial cracks in a thin hollow rotating functionally graded material (FGM) disk is of utmost interest. The disk is assumed to be isotropic with exponentially varying elastic modulus in the radial direction. The crack length and material gradation are the main parameters to be studied. The critical values of stress intensity factors in homogeneous and FGM disks are obtained. The results show that the SIF is highly dependent on the crack length and material gradation. © 2014 by Begell House, Inc.
Eskandari H.,Abadan Institute of Technology
Jordan Journal of Mechanical and Industrial Engineering | Year: 2014
This article focuses on the stress analysis of an internal crack located at an arbitrary position in a rotating functionally graded material disk. The disk is assumed to be isotropic with exponentially varying elastic modulus in the radial direction. A comprehensive study is carried out for various combinations of the crack length, direction, and location with the different gradation of materials. The results show that the material gradation, the crack position and the crack length have a significant influence on the value of stress intensity factors. Numerical results are given to assess the safety of the FGM and homogeneous cracked disks. © 2014 Jordan Journal of Mechanical and Industrial Engineering. © 2014 Jordan Journal of Mechanical and Industrial Engineering.
Hadi E.,Abadan Institute of Technology |
Rahim N.M.,Shiraz University
International Journal of Manufacturing, Materials, and Mechanical Engineering | Year: 2013
The problem of fatigue-crack-growth in a rotating disc at different crack orientation angles is studied by using an automated numerical technique, which calculates the stress intensity factors on the crack front through the three-dimensional finite element method. Paris law is used to develop the fatigue shape of initially semi-elliptical surface crack. Because of needs for the higher mesh density and accuracy near the crack, the sub-modeling technique is used in the analysis. The distribution of SIF's along the crack front at each step of growth is studied and the effect of crack orientation on the rate of crack-growth is investigated. The calculated SIF's are reasonable and could be used to predict the probable crack growth rates in fracture mechanics analysis and can help engineers to consider in their designing and to prevent any unwanted failure of such components. Copyright © 2013, IGI Global.
Bashiri E.,Abadan Institute of Technology
World Academy of Science, Engineering and Technology | Year: 2010
A 7-step method (with 25 sub-steps) to assess risk of air pollutants is introduced. These steps are: pre-considerations, sampling, statistical analysis, exposure matrix and likelihood, dose-response matrix and likelihood, total risk evaluation, and discussion of findings. All mentioned words and expressions are well-understood; however, almost all steps have been modified, improved, and coupled in such a way that a comprehensive method has been prepared. Accordingly, the SADRA (Statistical Analysis-Driven Risk Assessment) emphasizes extensive and ongoing application of analytical statistics in traditional risk assessment models. A Sulfur Dioxide case study validates the claim and provides a good illustration for this method.
Nouri-Taleghani M.,University of Tehran |
Kadkhodaie-llkhchi A.,University of Tabriz |
Karimi-Khaledi M.,Abadan Institute of Technology
Journal of Petroleum Geology | Year: 2015
Hydraulic flow units are defined as reservoir units with lateral continuity whose geological properties controlling fluid flow are consistent and different from those of other flow units. Because pore-throat size is the ultimate control on fluid flow, each flow unit has a relatively similar pore-throat size distribution resulting in consistent flow behaviour. The relations between porosity and permeability in terms of hydraulic flow units can be used to characterize heterogeneous carbonate reservoirs. In this study, a quantitative correlation is made between hydraulic flow units and well logs in South Pars gasfield, offshore southern Iran, by integrating intelligent and clustering methods of data analysis. For this purpose, a supervised artificial neural network model was integrated with multi-resolution graph-based clustering (MRGC) to identify hydraulic flow units from well log data. The hybrid model provides a more precise definition of flow units compared to definitions based only on a neural network. There is a good agreement between the results of well log analyses and core-derived flow units. The synthesized flow units derived from the well log data are sufficiently reliable to be considered as inputs in the construction of a 3D reservoir model of the South Pars field. © 2015 The Authors. Journal of Petroleum Geology © 2015 Scientific Press Ltd.