2018-10-23T21:33:05Z
http://ijmf.shirazu.ac.ir/?_action=export&rf=summon&issue=589
Iranian Journal of Materials Forming
IJMF
2015
2
2
Bending and Free Vibration Analyses of Rectangular Laminated Composite Plates Resting on Elastic Foundation Using a Refined Shear Deformation Theory
A. R.
Setoodeh
A.
Azizi
In this paper, a closed form solution for bending and free vibration analyses of simply supported rectangular laminated composite plates is presented. The static and free vibration behavior of symmetric and antisymmetric laminates is investigated using a refined first-order shear deformation theory. The Winkler–Pasternak two-parameter model is employed to express the interaction between the laminated plates and the elastic foundation. The Hamilton’s principle is used to derive the governing equations of motion. The accuracy and efficiency of the theory are verified by comparing the developed results with those obtained using different laminate theories. The laminate theories including the classical plate theory, the classical first-order shear deformation theory, the higher order shear deformation theory and a three-dimensional layerwise theory are selected in order to perform a comprehensive comparison. The effects of the elastic foundation parameters, orthotropy ratio and width-to-thickness ratio on the bending deflection and fundamental frequency of laminates are investigated.
Bending analysis
free vibration
Refined shear deformation theory
Two-parameter elastic foundation
2015
10
01
1
13
http://ijmf.shirazu.ac.ir/article_3236_cc933f118917c16ef3c4282802f99a87.pdf
Iranian Journal of Materials Forming
IJMF
2015
2
2
Effect of the Particle Size on the Deformation and Fracture Behavior of Al/4vol.%Al2O3 Composite Produced by Accumulative Roll Bonding (ARB)
M.
Reihanian
M.
Naseri
M.
Jalili Shahmansouri
In this study, Al/Al2O3 composites with two different particle sizes of 1 µm and 0.3 µm were produced via accumulative roll bonding (ARB). The microstructure evolution, mechanical properties and fracture behavior of the composites were investigated. Results show that higher ARB cycles are required to achieve a uniform distribution of particles in the composite with 0.3 µm particle size. During ARB, dense cluster of the particles broke up and a uniform distribution of particles was achieved after eight ARB cycles. The tensile strength of the composite with 1 µm and 0.3 µm particle size enhanced by increasing the number of ARB cycles, reached to about 170 MPa and 175 MPa, respectively, in comparison to that of the annealed Al (about 47 MPa). The finer particles caused a higher tensile strength due to the decrease in the distance between the particles at a given volume fraction. The fracture surface of both composites revealed ductile type fracture characterized by dimples. The dimples in the composite with particle size of 1 μm were larger and deeper.
Accumulative roll bonding (ARB)
Metal matrix composites (MMCs)
Microstructure
Mechanical properties
2015
10
01
14
26
http://ijmf.shirazu.ac.ir/article_3237_01aa4f0817836d8c80ab62eba897e617.pdf
Iranian Journal of Materials Forming
IJMF
2015
2
2
Investigation of Effective Parameters of the Two-Layer Sheet Hydroforming Process for Hollow Parts with Complex Geometry
M.
Saghari
A.
Afsari
Abstract<br />Hydroforming process is a deep stretching process only with the difference that a fluid is used instead of the mandrel. This paper investigates the hydroforming process of non-cylindrical and non-spherical geometries using finite element analysis software to calculate the influences of effective process parameters such as the coefficient of friction between the surfaces and the pressure applied during the process. Results of this process simulation indicate that decreasing the friction between surfaces, with an optimum lubrication, can decrease the changes in thickness which is related to sheet heightening this leads to a final product with more uniform thickness and more appropriate strength. On the other hand, it is observed that with pressure change there are very slight changes in the thickness for this geometry which can be neglected. The geometry of the mold also showed a great influence on the final quality of the formed sheet.<br />Keywords: sheet hydroforming, complex geometry, finite element analysis, friction, multistage pressure.
sheet hydroforming
complex geometry
finite element analysis
friction
multistage pressure
2015
10
01
27
34
http://ijmf.shirazu.ac.ir/article_3238_a82cba4597159c7ef5647c628600c43a.pdf
Iranian Journal of Materials Forming
IJMF
2015
2
2
Wave Propagation in Rectangular Nanoplates Based on a New Strain Gradient Elasticity Theory with Considering in-Plane Magnetic Field
M.
Janghorban
M. R.
Nami
In this paper, on the basis of a new strain gradient elasticity theory, wave propagation in rectangular nanoplates by considering in-plane magnetic field is studied. This strain gradient theory has two gradient parameters and has the ability to compare with the nonlocal elasticity theory. From the best knowledge of author, it is the first time that this theory is used for investigating wave propagation in nanoplates. It is also the first time that magnetic field is considered in modeling the wave propagation in rectangular nanoplates. In this article, an analytical method is adopted to achieve an exact solution for the governing equation. To verify the present methodology, our results are verified with the results published by present authors and other researchers. It is obtained that with the increase of static gradient parameter, the frequencies are increase. It is also shown that the phase velocities increase for the increase of magnetic field.
Aifantis’s strain gradient elasticity theory
Wave propagation
Magnetic field
Rectangular nanoplates
2015
10
01
35
43
http://ijmf.shirazu.ac.ir/article_3239_3a65c10f6ffcf5a6d3e1ca70c0486599.pdf
Iranian Journal of Materials Forming
IJMF
2015
2
2
Mechanical and Wear Properties of Al-Nip Composites Produced by ARB Process
H.
Baharipour
H.
Daneshmanesh
F.
Ghanbari Mardasi
In this research, Al-Ni particle composite strips are formed by accumulative roll bonding (ARB) process using Al strips and Ni powder. The rule of ARB cycles and volume percentage (Vol%) of Ni powder on the microstructure, wear resistance and mechanical properties of the formed composites are investigated. According to the tensile test results, the yield stress and tensile strengths of the Al -Ni (p) composites tend to increase with rising of the ARB cycles. Ductility of the ARB samples significantly decreased in the first cycle of the ARB process and then elevated lightly from the second pass of the ARB. Furthermore, the yield stress and tensile strengths of the Al - Ni (p) composites with different vol% of Ni powder, increased with increasing the amount of Ni Powder. Also the hardness and wear resistance of produced composites were investigated. Micro hardness and wear resistance of these composites increased with increasing the number of ARB cycles and the amount of Ni particles content during ARB Process.
Metal-matrix composites (MMCs)
Particle-reinforcement
Mechanical properties
Electron microscopy
2015
10
01
44
53
http://ijmf.shirazu.ac.ir/article_3272_9fa0db39afa5fbcd95c428a6105ff73c.pdf
Iranian Journal of Materials Forming
IJMF
2015
2
2
Optimization of thermomechanical parameters to produce an ultra-high strength compressor disk
M.
Aghaie-khafri
M.H.
Sheikh Ansary
Structural steels with very high strength levels are often referred to as ultrahigh-strength steels (UHSS). The usage of UHSS has been extensively studied in aerospace industries and offshore platforms. In this study, medium carbon low alloy steel (AMS6305) was thermomechanicaly treated to obtain an ultra-high strength bainitic steel for aircraft engine compressor disk. A novel themomechanical treatment was introduced to optimize microstructure and mechanical properties. By replacing the common quench-temper microstructure of compressor disk with bainite microstructure, an ultra-high strength bainitic steel was achieved. Based on the results obtained, the final microstructures following pre-deformation and subsequent heat treatment showed a very good combination of strength and toughness. Furthermore, it has been shown that austempering time and temperature play a major role in achieving ultra-high strength bainitic steels. The optimized strength and toughness was achieved by up quenching treatment. This is due to partitioning of prior austenite grains by tempered martensite plates.
Thermomechanical treatment
Bainite microstructure
Mechanical properties
Up quenching
2015
10
30
54
61
http://ijmf.shirazu.ac.ir/article_3273_4cb96e29d4893a0c2ab2ad41644b6b76.pdf