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An efficient design tool based on FEM for evaluating effects of components properties and operating conditions on interaction of tire with rigid road

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Journal of Central South University 2015年第1期22卷 189-195页

作者： moslem Namjoo Hossein Golbakhshi Department of Agricultural Machinery Engineering Faculty of AgricultureUniversity of Jiroft

It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety and effective driving action. In this work,an elaborated 3D model fully compliant with the geometrical size of radial tire 185/60 R15 is worked up, for evaluating the effects of components properties and working conditions on deformation and stress/strain fields created inside the tire. For the simulation, the tire structure is assumed to be composed of tread, carcass ply, and bead. The mechanical behavior of rubber as main component of tire is described by Mooney-Rivlin material model. The comparison of the obtained results and laboratory tests demonstrates the validity and high accuracy of analysis.

关键词： rubber simulation carcass ply stiffness Mooney-Rivlin model

Thermo-structural analysis on evaluating effects of friction and transient heat transfer on performance of gears in high-precision assemblies

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Journal of Central South University 2017年第1期24卷 71-80页

作者： Hossein Golbakhshi moslem Namjoo Department of Mechanical Engineering of Biosystems University of JiroftJiroft 78671-61167Iran

The high precision assemblies with considerable radial interference should be accompanied by heating and cooling ***,the mechanical properties of metals are greatly affected by thermal ***,for evaluating the stress distribution and distortion of teeth profiles in a gear/shaft assembly,a transient thermal analysis is necessary for finding the change in mechanical *** friction on the contact surface is another important parameter in interaction of the gear with the *** the gear stress and deformation fields for several modes of heat transfer and friction coefficients showed that the maximum radial or tangential stresses on contact surface of the joint may have more than 8%increase by increasing friction coefficient;while the intensity of heat transfer at cooling stage has lower effect on stress distribution.

关键词： friction coefficient transient heat transfer stress field distortion of teeth concurrent analyses

From furnace up to freezer:Elevational patterns of plant diversity in Mount Palvar,a semi-arid Irano-Turanian mountain range of southwest Asia

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Journal of Mountain Science 2024年第7期21卷 2236-2248页

作者： Atefeh GHORBANALIZADEH moslem DOOSTMOHAMMADI Kerman *** Iran

Much of the world's biodiversity lies in heterogeneous mountain areas with their diverse *** an example,Iranian montane ranges are highly diverse,particularly in the Irano-Turanian phytogeographical *** plant diversity patterns with increasing elevation is of high significance,not least for conservation *** studied the pattern of species richness,Shannon diversity,endemic richness,endemics ratio,and richness of life forms along a 3900 m elevational transect in Mount Palvar,overlooking the Lut Desert in Southeast *** also analyzed the effect of environmental variables on species turnover along the vertical gradient.A total of 120 vegetation plots(10 m×10 m)were sampled along the elevational transect containing species and environmental *** discover plant diversity pattern along the elevational gradient,generalized additive model(GAM)was ***-metric multidimensional scaling(NMDS)was applied for illustrating the correlation between species composition and environmental *** found hump-shaped pattern for species richness,Shannon diversity,endemic richness,and species richness of different life forms,but a monotonic increasing pattern for ratio of endemic species from low to high *** study confirms the humped pattern of species richness peaking at intermediate elevations along a complete elevational gradient in a semi-arid *** monotonic increase of endemics ratio with elevation in our area as a case study is consistent with global increase of endemism with *** to our results,temperature and precipitation are two important climatic variables that drive elevational plant diversity,particularly in seasonally dry *** study suggests that effective conservation and management are needed for this low latitude mountain area along with calling for long-term monitoring for species redistribution.

关键词： Elevational gradient Biodiversity Endemic Generalized additive model Hump-shaped pattern Irano-Turanian region

Microstructure and mechanical properties of SiC-particle-strengthening tri-metal Al/Cu/Ni composite produced by accumulative roll bonding process

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 357-364页

作者： moslem Tayyebi Beitallah Eghbali Department of Material Engineering Sahand University of Technology

In this study, a multilayer Al/Ni/Cu composite reinforced with Si C particles was produced using an accumulative roll bonding(ARB) process with different cycles. The microstructure and mechanical properties of this composite were investigated using optical and scanning microscopy and hardness and tensile testing. The results show that by increasing the applied strain, the Al/Ni/Cu multilayer composite converted from layer features to near a particle-strengthening characteristic. After the fifth ARB cycle, a composite with a uniform distribution of reinforcements(Cu, Ni, and SiC) was fabricated. The tensile strength of the composite increased from the initial sandwich structure to the first ARB cycle and then decreased from the first to the third ARB cycle. Upon reaching five ARB cycles, the tensile strength of the composite increased again. The variation in the elongation of the composite exhibited a tendency similar to that of its tensile strength. It is observed that with increasing strain, the microhardness values of the Al, Cu, and Ni layers increased, and that the dominant fracture mechanisms of Al and Cu were dimple formation and ductile fracture. In contrast, brittle fracture in specific plains was the main characteristic of Ni fractures.

关键词： accumulative roll bonding Al/Ni/Cu/SiC composite silicon carbide particles microstructure mechanical properties

Mathematical modeling of a slurry reactor for DME direct synthesis from syngas

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Journal of Natural Gas Chemistry 2012年第2期21卷 148-157页

作者： Sadegh Papari Mohammad Kazemeini moslem Fattahi Department of Chemical and Petroleum Engineering Sharif University of Technology

In this paper,an axial dispersion mathematical model is developed to simulate a three-phase slurry bubble column reactor for direct synthesis of dimethyl ether（DME） from *** large-scale reactor is modeled using mass and energy balances,catalyst sedimentation andsingle-bubble as well as two-bubbles class flow hydrodynamics.A comparison between the two hydrodynamic models through pilot plantexperimental data from the literature shows that heterogeneous two-bubbles flow model is in better agreement with the experimental data thanhomogeneous single-bubble gas flow ***,by investigating the heterogeneous gas flow and axial dispersion model for small bubblesas well as the large bubbles and slurry（*** paraffins and the catalyst） phase,the temperature profile along the reactor is *** between isothermal and non-isothermal reactors reveals no obvious performance difference between *** optimum values ofreactor diameter and height were obtained at 7 m and 50 m,*** effects of operating variables on the axial catalyst distribution,DME productivity and CO conversion are also investigated in this research.

关键词： modeling large-scale slurry bubble column optimization dimethyl ether synthesis single-bubble class two-bubbles class isotherm andnon-isotherm

Toward equation structural modeling:an integration of interpretive structural modeling and structural equation modeling

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Journal of Management Analytics 2021年第4期8卷 693-714页

作者： Alireza Amini moslem Alimohammadlou Department of Management Shiraz UniversityShirazIran

Interpretive structural modeling(ISM)is an interactive process in which a malformed(bad structured)problem is structured into a comprehensive systematic ***,despite many advantages that ISM provides,this method has some shortcomings,the most important one of which is its reliance on participants’intuition and *** problem undermines the validity of *** solve this problem and further enhance the ISM method,the present study proposes a method called equation structural modeling(ESM),which draws on the capacities of structural equation modeling(SEM).As such,ESM provides a statistically verifiable framework and provides a graphical,hierarchical and intuitive model.

关键词： decision analysis interpretive structural modeling structural equation modeling combined model

Influence of shielding gas on the mechanical and metallurgical properties of DP-GMA-welded 5083-H321 aluminum alloy

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International Journal of Minerals,Metallurgy and Materials 2016年第12期23卷 1416-1426页

作者： Amin Reza Koushki Massoud Goodarzi moslem Paidar Department of Metallurgy and Materials Engineering Iran University of Science and technology Department of Materials Engineering South Tehran Branch Islamic Azad University

In the present research, 6-mm-thick 5083-H321 aluminum alloy was joined by the double-pulsed gas metal arc welding （DP-GMAW） process. The objective was to investigate the influence of the shielding gas composition on the microstructure and properties of GMA welds. A macrostructural study indicated that the addition of nitrogen and oxygen to the argon shielding gas resulted in better weld penetration. Furthermore, the tensile strength and bending strength of the welds were improved when oxygen and nitrogen （at concentrations as high as approximately 0. 1vol%） were added to the shielding gas; however, these properties were adversely affected when the oxygen and nitrogen contents were increased further. This behavior was attributed to the formation of excessive brown and black oxide films on the bead surface, the formation of intermetallic compounds in the weld metal, and the formation of thicker oxide layers on the bead surface with increasing nitrogen and oxygen contents in the argon-based shielding gas. Analysis by energy-dispersive X-ray spectroscopy revealed that most of these compounds are nitrides or oxides.

关键词： aluminum alloys gas metal arc welding shielding gas mechanical properties metallurgical properties

Numerical simulation of tire/soil interaction using a verified 3D finite element model

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Journal of Central South University 2014年第2期21卷 817-821页

作者： Namjoo moslem Golbakhshi Hossein Department of Agricultural Machinery Engineering Faculty of AgricultureUniversity of Jiroft

The compaction and stress generation on terrain were always investigated based on empirical approaches or testing methods for tire/soil ***,the analysis should be performed for various tires and at different soil *** the increasing capacity of numerical computers and simulation software,finite element modeling of tire/terrain interaction seems a good approach for predicting the effect of change on the *** this work,an elaborated 3D model fully complianning with the geometry of radial tire 115/60R13 was established,using commercial code Solidwork *** hyper-elastic and incompressible rubber as tire main material was analyzed by Moony-Rivlin *** Drucker-Prager yield criterion was used to model the soil *** show that the model realistically predicts the laboratory tests outputs of the modeled tire on the soft soil.

关键词： tire/soil interaction finite element method(FEM) soil compaction stress distribution inflation pressure

A three dimensional CFD simulation and optimization of direct DME synthesis in a fixed bed reactor

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Petroleum Science 2014年第2期11卷 323-330页

作者： Fazel Moradi Mohammad Kazemeini moslem Fattahi Department of Chemical and Petroleum Engineering Sharif University of Technology Department of Chemical Engineering Abadan Faculty of Petroleum Engineering Petroleum University of Technology

In this study, a comprehensive three-dimensional dynamic model was developed for simulating the flow behavior and catalytic coupling reactions for direct synthesis of dimethyl ether （DME） from syngas including CO2 in a fixed bed reactor at commercial scale under both adiabatic and isothermal conditions. For this purpose, a computational fluid dynamic （CFD） simulation was carried out through which the standard κ-ε model with 10% turbulence tolerations was implemented. At first, an adiabatic fixed bed reactor was simulated and the obtained results were compared with those of an equivalent commercial slurry reactor. Then the concentration and temperature profiles along the reactor were predicted. Consequently, the optimum temperature, pressure, hydrogen to carbon monoxide ratio in the feedstock and the reactor height under different operation conditions were determined. Finally, the results obtained from this three-dimensional dynamic model under appropriate industrial boundary conditions were compared with those of others available in literature to verify the model. Next, through changing the boundary conditions, the simulation was performed for an isothermal fixed bed reactor. Furthermore, it was revealed that, under isothermal conditions, the performed equilibrium simulations were done for a single phase system. Considering the simultaneous effects of temperature and pressure, the optimum operation conditions for the isothermal and adiabatic fixed bed reactors were investigated. The results of the H2＋CO conversions indicated that, under isothermal condition, higher conversion could be achieved, in compared with that under adiabatic conditions. Then, the effects of various operating parameters, including the pressure and temperature, of the reactor on the DME production were examined. Ultimately, the CFD modeling results generated in the present work showed reasonable agreement with previously obtained data available in the literature.

关键词： Modeling CFD dimethyl ether synthesis dynamic behavior fixed-bed reactor isothermaland adiabatic conditions