negin ashrafi - Academia.edu (original) (raw)
Papers by negin ashrafi
Procedia Engineering, 2017
The silicon carbide particle reinforced aluminum matrix composites are expected to have many appl... more The silicon carbide particle reinforced aluminum matrix composites are expected to have many applications in aerospace, aircraft, automobile and electronic industries. Aluminium Silicon Carbide (Al-SiC) is also used for Advanced Microelectronic Packages. In this study, effect of different weight percentage of strontium on microstructure and mechanical properties of Al-SiC composite and Al-12Si (LM6) was investigated. In this research, scanning electron microscope equipped with EDS was used to define how modifier effect on microstructure. To fabricate Al-SiC composite, 10 wt% silicon carbide and different percentages (0.02, 0.5) Wt % of Al-10Sr was added to Al-11.6Si (LM6) by using vortex method for mixing the particles. The influence of adding different amount of Al-10Sr (0.01, 0.02, 0.5) Wt% on mechanical behavior of aluminum was also examined. The results found that UTS for aluminum increased by adding SiC and Sr. It was observed that the tensile for the composite did not increase dramatically. It was concluded the weak interface between particles and matrix, decreased the UTS. On the other hand strong interface between particles or fibers in the matrix showed high stiffness and strength but typically a low resistance to fracture.
Materials Chemistry and Physics, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
IOSR Journal of Mechanical and Civil Engineering, 2014
Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011.... more Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011. This review paper was written to study the robotics application in various industries mainly in pipeline inspection. This review paper was to fulfil the requirement of Automation and Robotics module assessment. The objectives of this review paper are; to observe different robotics applications in pipelines inspection, to learn the different design of robots in pipeline inspection, to outline the problems and adaptability improvements in the robotics application that was applied. The major problem of in-pipe inspection robots found is the different in diameter of pipes in any plant. And other problem relative to the inspection ways for different types of pipe applications.At the end of this review paper, it was concluded that improvements were seen in few designs of the robot example like the Parallelogram wheel leg.
Mechanics Based Design of Structures and Machines, May 5, 2021
In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of ... more In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of the angle-ply laminated curved panel under external excitation is presented. Hertz contact theory is...
IOSR Journal of Mechanical and Civil Engineering, 2014
Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the s... more Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the sustainability matters and it will play a important role in establishing a sustainable way ahead. This article defines sustainable manufacturing and design for sustainability. Sustainability can be incorporated into design, including design for environment, design for resources and energy, and design for sustainability and measuring energy consumption in manufacturing. An overview of current trends and new conceptions in the evolving of sustainable products developments by presenting Life Cycle Assessment method for products and processes, and optimization techniques for sustainable manufacturing processes will be presented.
Materials
An investigation into the addition of different weight percentages of Fe3O4 nanoparticles to find... more An investigation into the addition of different weight percentages of Fe3O4 nanoparticles to find the optimum wt.% and its effect on the microstructure, thermal, magnetic, and electrical properties of aluminum matrix composite was conducted using the powder metallurgy method. The purpose of this research was to develop magnetic properties in aluminum. Based on the obtained results, the value of density, hardness, and saturation magnetization (Ms) from 2.33 g/cm3, 43 HV and 2.49 emu/g for Al-10 Fe3O4 reached a maximum value of 3.29 g/cm3, 47 HV and 13.06 emu/g for the Al-35 Fe3O4 which showed an improvement of 41.2%, 9.3%, and 424.5%, respectively. The maximum and minimum coercivity (Hc) was 231.87 G for Al-10 Fe3O4 and 142.34 G for Al-35 Fe3O4. Moreover, the thermal conductivity and electrical resistivity at a high weight percentage (35wt.%) were 159 w/mK, 9.9 × 10−4 Ω·m, and the highest compressive strength was 133 Mpa.
Mechanics Based Design of Structures and Machines, 2021
In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of ... more In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of the angle-ply laminated curved panel under external excitation is presented. Hertz contact theory is...
Materials, 2020
Hybrid reinforcement’s novel composite (Al-Fe3O4-SiC) via powder metallurgy method was successful... more Hybrid reinforcement’s novel composite (Al-Fe3O4-SiC) via powder metallurgy method was successfully fabricated. In this study, the aim was to define the influence of SiC-Fe3O4 nanoparticles on microstructure, mechanical, tribology, and corrosion properties of the composite. Various researchers confirmed that aluminum matrix composite (AMC) is an excellent multifunctional lightweight material with remarkable properties. However, to improve the wear resistance in high-performance tribological application, hardening and developing corrosion resistance was needed; thus, an optimized hybrid reinforcement of particulates (SiC-Fe3O4) into an aluminum matrix was explored. Based on obtained results, the density and hardness were 2.69 g/cm3, 91 HV for Al-30Fe3O4-20SiC, after the sintering process. Coefficient of friction (COF) was decreased after adding Fe3O4 and SiC hybrid composite in tribology behaviors, and the lowest COF was 0.412 for Al-30Fe3O4-20SiC. The corrosion protection efficiency...
Applied Physics A, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Mechanics Based Design of Structures and Machines, 2019
Due to the rapid development of process manufacturing, composite materials with graphene-reinforc... more Due to the rapid development of process manufacturing, composite materials with graphene-reinforcement have obtained commercially notices in promoted engineering applications. For this regard, vibrational characteristics of a cylindrical nanoshell reinforced by graphene nanoplatelets (GPL) and coupled with piezoelectric actuator (PIAC) is investigated. Also, the nanostructure is embedded in a viscoelastic medium. The material properties of piece-wise graphene-reinforced composite (GPLRC) are assumed to be graded in the thickness direction of a cylindrical nanoshell and estimated through a nanomechanical model. For the first time in the current study is considering the effects of piezoelectric layer, viscoelastic foundation, GPLRC, and size-effects on the frequency responses of the GPLRC cylindrical nanoshell coupled with PIAC and by assuming perfect bonding between the core (GPLRC cylindrical shell) and the piezoelectric layer. The governing equations and boundary conditions have been developed using minimum potential energy and solved with the aid of the generalized differential quadrature method. In addition, because of piezoelectric layer, Maxwell's equation is derived. The results show that viscoelastic foundation, piezoelectric layer, GPL distribution pattern, length scale parameter and GPL weight function have important role in the frequency characteristics of the GPLRC cylindrical nanoshell coupled with PIAC and surrounded by viscoelastic foundation. The results of the current study are useful suggestions for design of materials science, micro-electro-mechanical systems, and nanoelectromechanical systems such as nanoactuators and nanosensors.
IOSR Journal of Mechanical and Civil Engineering, 2014
Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the s... more Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the sustainability matters and it will play a important role in establishing a sustainable way ahead. This article defines sustainable manufacturing and design for sustainability. Sustainability can be incorporated into design, including design for environment, design for resources and energy, and design for sustainability and measuring energy consumption in manufacturing. An overview of current trends and new conceptions in the evolving of sustainable products developments by presenting Life Cycle Assessment method for products and processes, and optimization techniques for sustainable manufacturing processes will be presented.
IOSR Journal of Mechanical and Civil Engineering, 2014
Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011.... more Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011. This review paper was written to study the robotics application in various industries mainly in pipeline inspection. This review paper was to fulfil the requirement of Automation and Robotics module assessment. The objectives of this review paper are; to observe different robotics applications in pipelines inspection, to learn the different design of robots in pipeline inspection, to outline the problems and adaptability improvements in the robotics application that was applied. The major problem of in-pipe inspection robots found is the different in diameter of pipes in any plant. And other problem relative to the inspection ways for different types of pipe applications.At the end of this review paper, it was concluded that improvements were seen in few designs of the robot example like the Parallelogram wheel leg.
International Journal of Production Economics, 1994
Today most firms are interested in a strategic approach for improving productivity and quality in... more Today most firms are interested in a strategic approach for improving productivity and quality in their organizations. Consistent with this thrust, this paper attempts to provide a strategic framework for such efforts. The main focus of this paper is on integrating various functional groups of a manufacturing organization and highlighting the role of new manufacturing concepts and technologies in such integrations. Comparison of earlier and present practices of production operations signifies the importance of JIT, TQM, and FMS in improving the integration of various functional areas and alignment between business, manufacturing and quality improvement strategies. The role of knowledge workers and support services play a dominant role in improving productivity and quality in manufacturing organizations, especially in advanced manufacturing systems such as JIT, FMS and CIM.
A study of the addition different weight percentages of strontium and its influence on the mechan... more A study of the addition different weight percentages of strontium and its influence on the mechanical properties and microstructure of Aluminum LM6 modified by (0.01, 0.02, 0.5) wt% strontium (Sr) was conducted, with the purpose of evaluating the properties of particulate silicon carbide (Sic), as reinforcement as well as the effect of a high Sr content. The obtained results indicated that addition of Al-10Sr improves the UTS and hardness of Aluminum and composite. Moreover, it is observed that adding Sr to the Al-SiC composite increased the amount of α-Al. The mechanical properties of the composite can be related to the volume fraction of dendritic α-Al, which can improve the mechanical properties of Aluminum or Al-Sic composite. it is concluded that the tensile for the composite did not increase dramatically because of weak interface between particles and matrix decrease the UTS, on the other hand strong interface between particles or fibers in the matrix show high stiffness and s...
Procedia Engineering, 2017
The silicon carbide particle reinforced aluminum matrix composites are expected to have many appl... more The silicon carbide particle reinforced aluminum matrix composites are expected to have many applications in aerospace, aircraft, automobile and electronic industries. Aluminium Silicon Carbide (Al-SiC) is also used for Advanced Microelectronic Packages. In this study, effect of different weight percentage of strontium on microstructure and mechanical properties of Al-SiC composite and Al-12Si (LM6) was investigated. In this research, scanning electron microscope equipped with EDS was used to define how modifier effect on microstructure. To fabricate Al-SiC composite, 10 wt% silicon carbide and different percentages (0.02, 0.5) Wt % of Al-10Sr was added to Al-11.6Si (LM6) by using vortex method for mixing the particles. The influence of adding different amount of Al-10Sr (0.01, 0.02, 0.5) Wt% on mechanical behavior of aluminum was also examined. The results found that UTS for aluminum increased by adding SiC and Sr. It was observed that the tensile for the composite did not increase dramatically. It was concluded the weak interface between particles and matrix, decreased the UTS. On the other hand strong interface between particles or fibers in the matrix showed high stiffness and strength but typically a low resistance to fracture.
Materials Chemistry and Physics, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
IOSR Journal of Mechanical and Civil Engineering, 2014
Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011.... more Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011. This review paper was written to study the robotics application in various industries mainly in pipeline inspection. This review paper was to fulfil the requirement of Automation and Robotics module assessment. The objectives of this review paper are; to observe different robotics applications in pipelines inspection, to learn the different design of robots in pipeline inspection, to outline the problems and adaptability improvements in the robotics application that was applied. The major problem of in-pipe inspection robots found is the different in diameter of pipes in any plant. And other problem relative to the inspection ways for different types of pipe applications.At the end of this review paper, it was concluded that improvements were seen in few designs of the robot example like the Parallelogram wheel leg.
Mechanics Based Design of Structures and Machines, May 5, 2021
In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of ... more In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of the angle-ply laminated curved panel under external excitation is presented. Hertz contact theory is...
IOSR Journal of Mechanical and Civil Engineering, 2014
Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the s... more Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the sustainability matters and it will play a important role in establishing a sustainable way ahead. This article defines sustainable manufacturing and design for sustainability. Sustainability can be incorporated into design, including design for environment, design for resources and energy, and design for sustainability and measuring energy consumption in manufacturing. An overview of current trends and new conceptions in the evolving of sustainable products developments by presenting Life Cycle Assessment method for products and processes, and optimization techniques for sustainable manufacturing processes will be presented.
Materials
An investigation into the addition of different weight percentages of Fe3O4 nanoparticles to find... more An investigation into the addition of different weight percentages of Fe3O4 nanoparticles to find the optimum wt.% and its effect on the microstructure, thermal, magnetic, and electrical properties of aluminum matrix composite was conducted using the powder metallurgy method. The purpose of this research was to develop magnetic properties in aluminum. Based on the obtained results, the value of density, hardness, and saturation magnetization (Ms) from 2.33 g/cm3, 43 HV and 2.49 emu/g for Al-10 Fe3O4 reached a maximum value of 3.29 g/cm3, 47 HV and 13.06 emu/g for the Al-35 Fe3O4 which showed an improvement of 41.2%, 9.3%, and 424.5%, respectively. The maximum and minimum coercivity (Hc) was 231.87 G for Al-10 Fe3O4 and 142.34 G for Al-35 Fe3O4. Moreover, the thermal conductivity and electrical resistivity at a high weight percentage (35wt.%) were 159 w/mK, 9.9 × 10−4 Ω·m, and the highest compressive strength was 133 Mpa.
Mechanics Based Design of Structures and Machines, 2021
In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of ... more In the presented study, maximum amplitude, frequency, and low-velocity impact characteristics of the angle-ply laminated curved panel under external excitation is presented. Hertz contact theory is...
Materials, 2020
Hybrid reinforcement’s novel composite (Al-Fe3O4-SiC) via powder metallurgy method was successful... more Hybrid reinforcement’s novel composite (Al-Fe3O4-SiC) via powder metallurgy method was successfully fabricated. In this study, the aim was to define the influence of SiC-Fe3O4 nanoparticles on microstructure, mechanical, tribology, and corrosion properties of the composite. Various researchers confirmed that aluminum matrix composite (AMC) is an excellent multifunctional lightweight material with remarkable properties. However, to improve the wear resistance in high-performance tribological application, hardening and developing corrosion resistance was needed; thus, an optimized hybrid reinforcement of particulates (SiC-Fe3O4) into an aluminum matrix was explored. Based on obtained results, the density and hardness were 2.69 g/cm3, 91 HV for Al-30Fe3O4-20SiC, after the sintering process. Coefficient of friction (COF) was decreased after adding Fe3O4 and SiC hybrid composite in tribology behaviors, and the lowest COF was 0.412 for Al-30Fe3O4-20SiC. The corrosion protection efficiency...
Applied Physics A, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Mechanics Based Design of Structures and Machines, 2019
Due to the rapid development of process manufacturing, composite materials with graphene-reinforc... more Due to the rapid development of process manufacturing, composite materials with graphene-reinforcement have obtained commercially notices in promoted engineering applications. For this regard, vibrational characteristics of a cylindrical nanoshell reinforced by graphene nanoplatelets (GPL) and coupled with piezoelectric actuator (PIAC) is investigated. Also, the nanostructure is embedded in a viscoelastic medium. The material properties of piece-wise graphene-reinforced composite (GPLRC) are assumed to be graded in the thickness direction of a cylindrical nanoshell and estimated through a nanomechanical model. For the first time in the current study is considering the effects of piezoelectric layer, viscoelastic foundation, GPLRC, and size-effects on the frequency responses of the GPLRC cylindrical nanoshell coupled with PIAC and by assuming perfect bonding between the core (GPLRC cylindrical shell) and the piezoelectric layer. The governing equations and boundary conditions have been developed using minimum potential energy and solved with the aid of the generalized differential quadrature method. In addition, because of piezoelectric layer, Maxwell's equation is derived. The results show that viscoelastic foundation, piezoelectric layer, GPL distribution pattern, length scale parameter and GPL weight function have important role in the frequency characteristics of the GPLRC cylindrical nanoshell coupled with PIAC and surrounded by viscoelastic foundation. The results of the current study are useful suggestions for design of materials science, micro-electro-mechanical systems, and nanoelectromechanical systems such as nanoactuators and nanosensors.
IOSR Journal of Mechanical and Civil Engineering, 2014
Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the s... more Manufacturing, as the main symbol of the civilized lifestyle, will be intensely affected by the sustainability matters and it will play a important role in establishing a sustainable way ahead. This article defines sustainable manufacturing and design for sustainability. Sustainability can be incorporated into design, including design for environment, design for resources and energy, and design for sustainability and measuring energy consumption in manufacturing. An overview of current trends and new conceptions in the evolving of sustainable products developments by presenting Life Cycle Assessment method for products and processes, and optimization techniques for sustainable manufacturing processes will be presented.
IOSR Journal of Mechanical and Civil Engineering, 2014
Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011.... more Robotics application has slowly increasing for the past 13 years. Much increase was seen in 2011. This review paper was written to study the robotics application in various industries mainly in pipeline inspection. This review paper was to fulfil the requirement of Automation and Robotics module assessment. The objectives of this review paper are; to observe different robotics applications in pipelines inspection, to learn the different design of robots in pipeline inspection, to outline the problems and adaptability improvements in the robotics application that was applied. The major problem of in-pipe inspection robots found is the different in diameter of pipes in any plant. And other problem relative to the inspection ways for different types of pipe applications.At the end of this review paper, it was concluded that improvements were seen in few designs of the robot example like the Parallelogram wheel leg.
International Journal of Production Economics, 1994
Today most firms are interested in a strategic approach for improving productivity and quality in... more Today most firms are interested in a strategic approach for improving productivity and quality in their organizations. Consistent with this thrust, this paper attempts to provide a strategic framework for such efforts. The main focus of this paper is on integrating various functional groups of a manufacturing organization and highlighting the role of new manufacturing concepts and technologies in such integrations. Comparison of earlier and present practices of production operations signifies the importance of JIT, TQM, and FMS in improving the integration of various functional areas and alignment between business, manufacturing and quality improvement strategies. The role of knowledge workers and support services play a dominant role in improving productivity and quality in manufacturing organizations, especially in advanced manufacturing systems such as JIT, FMS and CIM.
A study of the addition different weight percentages of strontium and its influence on the mechan... more A study of the addition different weight percentages of strontium and its influence on the mechanical properties and microstructure of Aluminum LM6 modified by (0.01, 0.02, 0.5) wt% strontium (Sr) was conducted, with the purpose of evaluating the properties of particulate silicon carbide (Sic), as reinforcement as well as the effect of a high Sr content. The obtained results indicated that addition of Al-10Sr improves the UTS and hardness of Aluminum and composite. Moreover, it is observed that adding Sr to the Al-SiC composite increased the amount of α-Al. The mechanical properties of the composite can be related to the volume fraction of dendritic α-Al, which can improve the mechanical properties of Aluminum or Al-Sic composite. it is concluded that the tensile for the composite did not increase dramatically because of weak interface between particles and matrix decrease the UTS, on the other hand strong interface between particles or fibers in the matrix show high stiffness and s...