The first page
text
article
2018
per
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
https://jstc.iust.ac.ir/article_30756_0aa06f53e5ab73b6660d1203b8cde449.pdf
dx.doi.org/10.22068/jstc.2018.30756
Modeling and intelligent control of vibration of cantilever composite plate embedded with shape memory alloy wires
Shima sadat
Mojabi
Department of Mechatronic Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
author
Mohammad Mahdi
Kheirikhah
Faculty of Industrial and Mechanical Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
author
text
article
2018
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The purpose of this study is controlling the forced vibration of a layered composite cantilever plate embedded with shape memory alloys wires using classical and fuzzy controllers. The governing equations of motion of the composite plate including shape memory alloy wires are calculated using the classical laminated plate theory and the Hamilton principle. The Liang formula is also used to model the thermo-mechanical behavior of the shape memory alloys wire actuators. Then, the free vibration solution for the layered composite plate is calculated using semi-analytical Rayleigh-Ritz method and then is compared with experimental method. Comparison between the obtained natural frequencies of the composite plate and those of published experimental results confirms the accuracy of the purposed modeling and solution. Finally, three controlling system are designed to reduce the amplitude of vibrational displacement of the structure against forced vibrational excitations including PID controller, Fuzzy controller and PID-Fuzzy controller. Finally, the genetic algorithm is used to optimize the gain coefficients of the classic controller and the rules and parameters of the fuzzy controller to reduce the vibrational displacement amplitude of the plate. The obtained results show that the all designed controllers can reduce the steady-state vibrational displacement amplitude of the plate significantly, but the PID-Fuzzy controller has the best performance.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
363
374
https://jstc.iust.ac.ir/article_28554_370b9cad69e3686985b2245c52c1bc21.pdf
dx.doi.org/10.22068/jstc.2018.28554
Stress analysis of single-lap bonded joints in composite tubes
under torsion and hygrothermal effects using DQM
Mohammad Mansour
Mohieddin Ghomshei
Department of Mechanical Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran
author
Reza
Shahi
Department of Mechanical Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran
author
text
article
2018
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In this research, adhesively tubular single lap joints subjected to torsional and hygrothermal loadings are studied using the Differential Quadrature Method (DQM), in which the lateral deflections are taken into account. The analysis is based on the linear cylindrical shell theory. At first, governing differential equations of the tubes and the interfacing adhesive layer are expressed in terms of the displacement field components. The total structure is divided into the overlapping and non-overlapping areas. The differential equations of the overlapping area which do not have closed form solution, are discretized by implementing the DQM. Then, the equations of the total areas are solved simultaneously regarding their boundary and continuity equations, to find the circumferential and radial (lateral) displacements. Next, having known the displacement field components, the distribution of the peel and shear stresses in the interfacing adhesive are calculated. Results obtained from the presented DQM solutions are compared well with those of a published reference as well as those of an ABAQUS finite element model. Finally, using the DQM model, the influence of the adhesive layer thickness, the overlap length, and the changes in the temperature and relative humidity on the interfacing stress distributions are investigated.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
375
385
https://jstc.iust.ac.ir/article_23927_1e3ccf8f96da7a08998270762ca9bd27.pdf
dx.doi.org/10.22068/jstc.2018.23927
A study on effect of titanium dioxide nanoparticles on the elastic modulus, impact and tensile strengths of polypropylene/linear low density polyethylene (PP/LLDPE) blends
Faramarz
Ashenai Ghasemi
Faculty of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
author
Ismail
Ghasemi
Department of polymer Engineering, Polymer and Petrochemical Institute (IPPI), Tehran, Iran
author
Sajjad
Daneshpayeh
Faculty of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
author
text
article
2018
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In this study, mechanical properties, including elastic modulus and impact strength of nanocomposites based on polypropylene and polyethylene, linear low-density blends, in the presence of titanium oxide nanoparticles have been studied. 0, 2 and 4 wt% titanium dioxide nanoparticles were added to the basic ingredients polypropylene / polyethylene linear low density with a fixed ratio of 60/40 wt. % to reach the final composition that was prepared using an extruder. Tensile and impact tests were carried out in order to determine the elastic modulus and impact strength of compounds. It was observed that the presence of titanium dioxide nanoparticles at 2 wt. %, elastic modulus and impact strength compared to the basic polypropylene/polyethylene linear low-density increase and the presence of higher level of titanium dioxide nanoparticles up to 4 wt. % decrease mechanical properties of compounds. It was also seen that usilng low weight percent of nano particles, increase impact strength of the samples up to 7 percenrt.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
386
390
https://jstc.iust.ac.ir/article_23928_caf6c537e19a3345a19bd5bae64611f3.pdf
dx.doi.org/10.22068/jstc.2018.23928
Effect of preheating temperature on thickness and interfacial microstructure of Aluminum-Copper bimetallic composite produced by vertical centrifugal casting
Ehsan
Hiteh
Department of Materials Engineering, Islamic Azad University of Karaj, Karaj, Iran
author
Mehdi
Divandari
School of Materials Engineering, Iran University of Science and Technology, Tehran, Iran
author
Morteza
Gholami
School of Materials Engineering, Iran University of Science and Technology, Tehran, Iran
author
text
article
2018
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Application of composites of two or more metals has been increased, aiming to increase productivity, in various sectors of industry in recent years. In this work an Al/Cu bimetallic composite was prepared by casting Al melt into a Cu bush with 40 mm height and 79 and 84 inner and outer diameters, rotating at 1480 revolutions per minute (rpm), and 100, 150, 200, 300, and 400°C preheating temperature, respectively in a vertical centrifugal casting machine. Cooling rate increment, due to lower preheating temperature, not only lead to interface thinning but also it can modify microstructure. The results of scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis showed that four discrete layers have been formed from the Cu side, including AlCu2, AlCu, Al2Cu continuous layers, Al2Cu precipitates scattering in anomalous eutectic structures and finally α-Al/Al3Cu anomalous eutectic structure near the Al side. Micro hardness measurements showed that hardness of various presented phases decreases from outward to the inward.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
391
398
https://jstc.iust.ac.ir/article_25629_5f6135330052a083476028b38ac25048.pdf
dx.doi.org/10.22068/jstc.2018.25629
Experimental study of tensile behavior of self-healing fiber-metal laminates composites with chopped hollow glass fibers
Reza
Eslami-Farsani
Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
author
Fatemeh
Mohabbati
Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
author
Hamed
Khosravi
Department of Materials Engineering, University of Sistan and Baluchestan, Zahedan, Iran
author
text
article
2018
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Fiber metal laminates (FMLs) are a family of hybrid composite structures formed from the combination of metal layers sandwiching a fiber- reinforced plastic layer. Because of low weight and better mechanical properties in comparison with aluminum alloys and other composites, they have found a wide range of use in aerospace industriy. In the case of deep micro-cracks within the FMLs, they must be replaced. To avoid of replacing the FMLs, the self-healing phenomenon is an appropriate strategy to control the defects and micro-cracks. In this research a series of chopped micro glass tubes were employed to provide a self-healing system. These chopped micro glass tubes were filled with epoxy resin + hardener as a healing agent system. When the structure is exposed under loading condition, the created damages and micro-cracks rupture the chopped micro-glass tubes and the healing agent flows in the damage area and over a time span the defects will be healed and eliminated. The aim of this study is to find out the appropriate chopped micro-glass tubes volume fraction and the healing time to obtain an efficient healing. For this purpose, the chopped micro-tubes containing 4, 8, and 12 Vol.% were incorporated in epoxy- glass fibers composite and the tensile behavior observed for the specimens were assessed during different healing time. The highest healing efficiency of 58.3% was observed for the specimen with 8% healing agent.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
399
404
https://jstc.iust.ac.ir/article_25631_931ce498b5e09230513d859bc684e231.pdf
dx.doi.org/10.22068/jstc.2018.25631
Buckling of composite plate made of curvilinear fiber with linear and nonlinear fiber orientation variation
Hossein
Nopour
Department of Science and Marine Engineering, Malek Ashtar University of Technology, Shahinshahr, Iran
author
Abdulreza
Kabiri Ataabadi
Department of Science and Marine Engineering, Malek Ashtar University of Technology, Shahinshahr, Iran
author
Mahmood Mehrdad
Shokrieh
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
author
text
article
2018
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In this research, effect of curvilinear fibers on the buckling load improvement of composite plates was studied. Two paths for curvilinear fiber were considered, namely, the linear variation of fiber angle and the nonlinear variation of fiber angle (constant curvature). The fiber orientation varies linear and nonlinear with the coordinates of plate in these two mentioned paths respectively. In the previous researches, linear variation of fiber angle was usually investigated. However, the results were not compared with those of the other paths. In this research, comparisons between the two paths of the linear variation of fiber orientation and the constant curvature of composite plates with and without cutout were performed. ABAQUS finite element software was used for modeling and analysis. Results show that for composite plates without cutouts and with intended dimensions, material, lay-up and boundary conditions in the ideal state, the linear variation of fiber orientation caused ten percent increase in the buckling load in comparison with the constant curvature path. However, by considering the minimum practical radius constraint of the manufacturing method, the constant curvature path shows better results. According to applied boundary conditions, the mechanism of buckling load increase with curvilinear fibers is due to shifting the load from the center of plate to the side edges. Two geometries of cutout, circular cutout with different diameters and elliptical cutout with different aspect ratios were also considered. The results show that in the models with cutout by considering the manufacturing constraints, both paths have similar buckling load approximately.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
405
417
https://jstc.iust.ac.ir/article_25635_3f803fd3b42779bc52cc79fa144b5ed9.pdf
dx.doi.org/10.22068/jstc.2018.25635
Experimental and numerical analysis of composite lattice truncated conical structures with and without carbon nanotube reinforcements under axial compressive force
Ali
Davar1
Composite Research Centre, Malek-e-Ashtar University, Tehran, Iran
author
Reza
Azarafza2
Department of Materials and Manufacturing, Malek-e-Ashtar University, Tehran, Iran
author
Vahid
Bagheri
Department of Mechanical Engineering, Sharif University of Technology, Golpaygan, Iran
author
text
article
2018
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In the present paper the compressive behavior of composite lattice truncated cone reinforced with and without carbon nanotube (CNT) is investigated using experimental and numerical simulation methods. Composite lattice truncated cone samples, made of glass/epoxy without CNT and reinforced with 2% wt. CNT are fabricated using filament winding process and tested under compressive axial force. Moreover, modeling of the structure is performed and numerical simulation is achieved using commercial finite element ABAQUS software and the results of compressive force vs. axial displacement are verified by the experimental data and good agreement is observed. Halpin-Tsai micromechanics model is also utilized in order to calculate the nanocomposite material properties and assigned in the numerical simulation. The effects of CNT weight percentage and coefficients of CNT dispersion within the epoxy resin matrix are investigated using numerical simulation method. The results showed that addition of CNT by 2% wt. to the epoxy resin of the composite lattice conical structure, enhanced the maximum carried compressive force by 44%. While addition of CNT more than 2% wt. causes the compressive strength to be decreased due to less dispersion quality and agglomeration and non-uniform dispersion of the CNTs within the epoxy resin.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
418
425
https://jstc.iust.ac.ir/article_26375_136b6b844bc6f7e3a4b9368a0e76a00f.pdf
dx.doi.org/10.22068/jstc.2018.26375
Investigation the mechanical and microstructural propreties of copper surface composite Cu/SiO2 fabricated by friction stir processing
elaheh
khodabakhshi
Department of Material Engineering, Bu Ali Sina University, Hamedan, Iran
author
Shahab
Kazemi
Department of Material Engineering, Bu Ali Sina University, Hamedan, Iran
author
saeed
ahmadifard
Department of Material Engineering, Bu Ali Sina University, Hamedan, Iran
author
text
article
2018
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Abstract Friction stir processing (FSP) is a method for improvement surface. This process development for refinement of microstructure, improvement of materials mechanicals properties so production of surfsce composite. The aim of article product metal matrix composite (MMC) on surface of copper sheets by means of SiO2 refinement by friction stir processing for improve mechanical properties. In this article travel speed was fixed and56 mm/min and rotationals speed were 500, 710, 1000 rpm to sue. Optimum sample selected due to microstructure resualts and highest mechanical properties. Microstructure resualts reported by optical and scaning electron microscopical. Resualt indicating via increase rotational speed, increase size and decrase hardness. Maximum hardness related to specimen whit rotational speed 500 rpm, and 121 Hv, least size 10µm. so tensile properties statement white standard tensile test. Resualt of mechanichal surface composite were about on 218 to 227 Mpa respectively. At last wear properties of surface composite were investigated. The resualt of wear test exhibiting better wear behaviour of the developed composite.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
426
433
https://jstc.iust.ac.ir/article_28249_37dfb9372e785b4a5511af0f677a1e04.pdf
dx.doi.org/10.22068/jstc.2018.28249
Experimental Investigation of Dynamic Behavior of Composite Sandwich Panel Using Self-healing Materials under CHARPY impact and 3-point Bending Destruction
Navid
Jalalian Mirzapour
Department of Mechanical Engineering, Islamic Azad University South Branch, Tehran, Iran
author
mehdi
Yarmohammad Tooski
Department of Mechanical Engineering, Islamic Azad University South Branch, Tehran, Iran
author
text
article
2018
per
In this research, CHARPY impact behavior of sandwich panel using the self-healing materials is considered. The sandwich panel consists of a PVC solid foam core between Carbon fibers composite faces with lay-up (0/90)s at the top and down structure. The thin glass tubes are filled by the self-healing materials and put among the composite layers of sandwich panel. The sandwich panel construction is made of handy lay-up, using Epoxy to bond the layers. The self-healing materials with (0.5, 1, 1.5) volume fraction are used among composite layers of sandwich panel. The destruction of sandwich panel using the self-healing materials is carried out by three point bending. After destruction, the healing will be started from zero point then 3 to 7 days have been considered to determine the effect of the self-healing materials of sandwich panel. CHARPY impact test are performed on the specimens at the mentioned time to investigate the effect of the self-healing material on the impact behavior of sandwich panel. The experimental results of CHARPY impact behavior of sandwich panel considering the self-healing materials illustrates that the most dynamic fracture toughness and healing efficiency belong to the specimen with 1.5 volume fraction after 7 days from destruction time comparing the control specimen. Using glass tubes particularly and the quantity of tubes also will be significant effect on increasing the strength of construction. By increasing the volume fraction and the time of healing, the healing efficiency of sandwich panel will be enhanced as well.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
434
442
https://jstc.iust.ac.ir/article_28558_a181d79dea3461a9db4f3e59827fe206.pdf
dx.doi.org/10.22068/jstc.2018.28558
Effect Of Dimensions Smart Attached Mass And Local Stiffness On Dynamic Response Of Thick Plates
Keramat
Malekzadeh Fard
Department of Aerospace Engineering, MalekAshtar University of Technology, Tehran, Iran
author
Naser
Zolghadr
Department of Aerospace Engineering, MalekAshtar University of Technology, Tehran, Iran
author
Ali Reza
Pourmoayed
Department of Aerospace Engineering, MalekAshtar University of Technology, Tehran, Iran
author
text
article
2018
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This article for the first time is concerned with effects of parameters as local smart stiffness and smart attached mass dimensions of dynamic behavior of thick laminated plates with attached mass. In deriving governing equations, Gark-Kant’s higher order theory is used and effects of SMA and attached mass`s stiffness taken into account and finally vibration equations of thick plate carrying attached mass contain SMA is reached by using Hamilton`s principal. Then by means of Galerkin method, mass and stiffness matrices are extracted for achieving to a standard eigenvalue vibration problem. In this problem simply supported boundary condition is used for each four edges. Some important parameters such as ratio of local stiffness to stiffness of host structure and smart attached mass dimension on main frequencies of laminated thick plate is studied. A Comparative result with those in published references is presented. These numerical results show that local stiffness due to smart attached mass has a great role on dynamic behavior of thick laminated plates that if SMA didn`t active properly or ignore the effect of attached mass`s stiffness the dynamic response of system will have a lot of changes.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
443
452
https://jstc.iust.ac.ir/article_29902_37fc7f0353a9ce2b30e4b2ee50a617ac.pdf
dx.doi.org/10.22068/jstc.2018.29902
Visualization of Flow & Void In pultrusion Process of thermoplastic composites
amirhossein
dadou
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
author
Mohammad
Golzar
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
author
Davood
Akbari
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
author
Mohammad Hosain
Mohamadipour
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
author
text
article
2018
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Pultrusion is a continuous method for producing profiles with a constant cross section. Mechanical Properties of pultruded composite is related to process parameters such as pulling velocity, Temperature of die, texture of reinforced fibers, etc. Visualization of Physical variables such as velocity of melted resin, position of backward melt flow, orientation of reinforced fiber in the die can be useful in estimation of degree of impregnation and estimation of quality of pultruded composite. visualization and optimization of these parameters can be a major step to achieve pultruded composite with requested specifications and better performance. In this research, pultrusion die with glass walls has been used for direct observation of process during pultrusion. glass die has been heated using IR radiation. In this way important parameters such as, position of molten backflow, velocity profile of melted resin, orientation of reinforced fibers and void state have been observed directly and volume of voids among the die has been reducted about 0.17 instead of first volume and Impregnation Ratio in Y Direction calculated 0.05 * 10-5 m2 and Vx=0.43cm/s ,Vy=0.05cm/s.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
453
463
https://jstc.iust.ac.ir/article_29903_1ddc3452c25d471137b96028e6521889.pdf
dx.doi.org/10.22068/jstc.2018.29903
The investigation and comparison of mechanical propertise and microstructure Al/CNT and Al/CNT/Al2O3 copmosites produced by mixed accumulative roll bounding
Ali
Tabesh
Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar, Iran.
author
Gholamreza
Ebrahimi
- Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar, Iran
author
hamid
ezatpor
2- Faculty of Engineering, Sabzevar University of New Technology, , Iran
author
text
article
2018
per
Accmulative roll bonding prcess is one of severe plastic deformation procidures for produce high strength-ultrafine grain materials. In this investigation, the new method of mixed accumulative roll bonding was used to produce Al-based composite reinforced with carbon nanotube and alumina. This method is mixed of Continual Annealing roll Bonding and cross roll accumulative roll bonding procedures. This process has two steps. The first step is reinforcement adding with accumulative roll bonding in four rolling passes and annealing for one hour and 350°C after any pass. The next step is accumulative roll bonding without adding reinforcement and annealing. After any rolling pass, strips rotate 90° in each step and then rolled. In this process 11 rolling passes perform on Al/(1%wt CNT) composite and 9 rolling passes on Al/(1%wt)CNT/(2%wt) AL2O3 composite. X-ray diffraction result show that grain size is about nanometer in final rolling pass for both composite and with increase pass number increases tensile strength and elongation decrease first and then increases. strenght in Al/CNT/Al2o3 composite is higher than Al/CNT composite at the same rolling pass. FESEM picture show that reinforced distribution was well in final rolling pass.
Journal of Science and Technology of Composites
Iran University of Science and Technology
2383-3823
4
v.
4
no.
2018
464
470
https://jstc.iust.ac.ir/article_30034_d989a63f9bc9521b07dee8447536c6d5.pdf
dx.doi.org/10.22068/jstc.2018.30034