2024-03-28T16:15:33Z
https://jmee.isme.ir/?_action=export&rf=summon&issue=4106
Iranian Journal of Mechanical Engineering Transactions of the ISME
JMEE
1605-9727
1605-9727
2015
16
2
Spreading of Plastic Zones in Functionally Graded Spherical Tanks Subjected to Internal Pressure and Temperature Gradient Combinations
abbas
heydari
Thermo-Elasto-Plastic analyses of thick-walled spherical tanks made of functionally graded materials are investigated analytically. These tanks are subjected to positive or negative temperature gradient and internal pressure loadings separately or simultaneously. The power law modeling has been used for through-the-thickness variation of mechanical properties. von Mises yield criterion and Elastic-Perfectly-Plastic assumptions are used for describing the material behavior in plastic zones. The patterns of plastic zones spreading for various combinations of internal pressure and positive or negative temperature gradient are investigated. Numerical analyses conducted for the similar problems and excellent agreement with the analytical solutions observed. FG sphere subjected to internal pressure and negative temperature gradient yields at a lower pressure than the FG sphere subjected to internal pressure. Internal pressure and negative temperature gradient combination is the most critical loading combination and positive temperature gradient increases the capacity of FG spherical tank subjected to internal pressure.
analytical analyses
Thermo-Elasto-Plastic stresses
functionally graded spherical reservoir
temperature gradient
internal pressure
2015
09
01
5
25
https://jmee.isme.ir/article_24903_0a771040b014258d646495624badf4b9.pdf
Iranian Journal of Mechanical Engineering Transactions of the ISME
JMEE
1605-9727
1605-9727
2015
16
2
A New Model of Car Following Behavior Based on Lane Change Effects Using Anticipation and Evaluation Idea
Alireza
Khodayari
ali
ghaffari
ali
kamali
farzam
tajdari
This paper aims to investigate a new and intricate behavior of immediate follower during the lane change of leader vehicle. Accordingly, the mentioned situation is a transient state in car following behavior during which the follower vehicle considerably deviates from conventional car following models for a limited time, which is a complex state including lateral and longitudinal movement simultaneously.Based on closer inspection of microstructure behavior of real drivers, this transient state is divided into two stages of anticipation and evaluation. Afterwards, a novel adaptive neuro-fuzzy model considering human driving factors is proposed to simulate the behavior of real drivers. Comparison of model results and real traffic data shows that the proposed model can describe anticipation and evaluation behavior during a car following behavior with acceptable errors which leads to enhancement of car following applications like driving assistant and collision avoidance systems.
Evaluation
Car following
Intelligent model
ANFIS
human driving factors
2015
09
01
26
38
https://jmee.isme.ir/article_24902_52c3d4b0b72ace3b12c5887567a75559.pdf
Iranian Journal of Mechanical Engineering Transactions of the ISME
JMEE
1605-9727
1605-9727
2015
16
2
Mechanical and Thermal Stresses In a Linear Plastic FGM Hollow Cylinder Due to Axisymmetric Loads
Milad
Shokouhfar
Mohammad reza
Eslami
Mohsen
Jabbari
Atefeh
Hatefkia
In this paper, an analytical solution for computing the linear plastic stresses and critical temperature and pressure in a FGM hollow cylinder under the internal pressure and temperature is developed. It has been assumed that the modulus of elasticity and thermal coefficient of expansion were varying through thickness of the FGM material according to a power law relationship. The Poisson's ratio was considered constant throughout the thickness. The general form of thermal and mechanical boundary conditions is considered on the inside surfaces. In the analysis presented here the effect of non-homogeneity in FGM cylinder was implemented by choosing a dimensionless parameter, named m, which could be assigned an arbitrary value affecting the stresses in the cylinder. Distribution of stresses in radial and circumferential directions for FGM cylinders under the influence of internal pressure and temperature gradient were obtained. Graphs of variations of stress, critical temperature and pressure versus radius of the cylinder were plotted. Cases of pressure, temperature loadings were considered separately. The direct method is used to solve the heat conduction and Navier equations.
Hollow Cylinder
non-homogenous
axisymmetric
FGM
Elastic-Plastic Analysis
2015
09
01
39
65
https://jmee.isme.ir/article_24904_7d2a20b80204be149a7a41de16f8076b.pdf
Iranian Journal of Mechanical Engineering Transactions of the ISME
JMEE
1605-9727
1605-9727
2015
16
2
Friction stir spot welding of polycarbonate by a new design tool
Eisa
Khoran
Mohammad
Khoran
Seied Mostafa
Mousavizade Noghabi
Microstructures, tensile properties and fracture energy of a friction stir spot welded polycarbonate (FSSW) were studied at varying rotational rates and dwelling time. The problem of common FSSW welding is the remaining of characteristic keyhole. This can act as a concentration place in mechanical tests. To order solve this problem authors took advantage of innovation for designing the welding tool. The results show that in constant dwell time, strengths increase until 800 rpm and then decreases. In constant rotational speed (400, 800) the strength increase by increasing in dwell time but in 1600 rpm the best result was achieved in 10 Sec dwell time. Fracture energy which was exploit from stress-strain curve were in good agreement with strength of welds.
Friction stir spot welding
Polycarbonate
Tensile strength
Tool without pin
characteristics keyhole
2015
09
01
66
76
https://jmee.isme.ir/article_24905_32fbe6213b25190f2cb866a4a4e2ef3f.pdf
Iranian Journal of Mechanical Engineering Transactions of the ISME
JMEE
1605-9727
1605-9727
2015
16
2
Fracture Analysis of a FGM Strip Containing Multiple Interface Cracks Sandwiched between Two Homogeneous Layers
rasul
bagheri
hossein
lak
A FGM layer sandwiched between two isotropic layers weakened by several interface cracks under antiplane loading is studied. This paper examines the modelling of cracks by distribution of strain nuclei along crack lines. In this investigation, the Volterra-type screw dislocation employed between FGM and an elastic layer. To solve the dislocation problem, the complex Fourier transform is applied. One merit of this technique is the possibility to determination of the stress intensity factors for multiple cracks. The system of equations is derived by considering the distribution of line dislocation on the crack. These equations are of Cauchy singular type at the location of dislocation, which can be solved numerically to obtain the dislocation density on the faces of the cracks. Several examples are solved and the stress intensity factors are obtained. The effect of the properties and cracks geometries on the mode III stress intensity factor are studied and the validity of analysis is checked.
Multiple interface cracks
Functionallay graded layer
Singular integral equations
Stress intensity factors
Distributed dislocation tecchnique
2015
09
01
77
91
https://jmee.isme.ir/article_24907_f7dd6af4943c9e49106587f7703ca742.pdf