The distribution–allocation problem is known as one of the most comprehensive strategic decisions.In real-world cases,it is impossible to solve a distribution–allocation problem completely in acceptable time.This fo...The distribution–allocation problem is known as one of the most comprehensive strategic decisions.In real-world cases,it is impossible to solve a distribution–allocation problem completely in acceptable time.This forces the researchers to develop efficient heuristic techniques for the large-term operation of the whole supply chain.These techniques provide near optimal solution and are comparably fast particularly for large-scale test problems.This paper presents an integrated supply chain model which is flexible in the delivery path.As solution methodology,we apply a memetic algorithm with a novelty in population presentation.To identify the optimum operating condition of the proposed memetic algorithm,Taguchi method is adopted.In this study,four factors,namely population size,crossover rate,local search iteration and number of iteration,are considered.Determining the best level of the considered parameters is the outlook of this research.展开更多
We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were use...We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.展开更多
The strength of the mould cavity in sand casting is very much significant to attain high-quality castings. Optimization of green sand process parameters plays a vital role in minimizing casting defects. In the present...The strength of the mould cavity in sand casting is very much significant to attain high-quality castings. Optimization of green sand process parameters plays a vital role in minimizing casting defects. In the present research work, the effect of process parameters such as AFS grain fineness number, water, molasses, bentonite, fly ash, and ramming, and their levels on the resultant mould properties were investigated and optimized using Taguchi based grey relational analysis. The Taguchi L18 orthogonal array and analysis of variance(ANOVA) were used. The quality characteristics viz., green compression strength, permeability, bulk density, mould hardness and shatter index of green sand mould were optimized using grey relational grade, based on the experiments designed using Taguchi's Design of Experiments. ANOVA analysis indicated that water content is the most influential parameter followed by bentonite, and degree of ramming that contributes to the quality characteristics. The results are confirmed by calculating confidence intervals, which lies within the interval limits. Finally, microstructure observations and X-ray diffraction analysis have been performed for the optimal sand parametric combination. Results show that presence of maximum amount of SiO_2, which might be the reason for enhancement of the physical properties of the sand.展开更多
Compared with conventional manufacturing methods, the additive manufacturing technique enhances mechanical properties. The present investigation of additive manufacturing technique is focused on delamination studies o...Compared with conventional manufacturing methods, the additive manufacturing technique enhances mechanical properties. The present investigation of additive manufacturing technique is focused on delamination studies of Onyx-Glass Fiber Hybrid Polymer Composite(OGFHPC) along with surface roughness properties during machining(drilling) of composites through abrasive water jet machining(AWJM). However, delamination is a major issue during machining of OGFHPC. In order to overcome these drawbacks, the fabrication of OGFHPC was carried out using fused deposition modeling(FDM) technology which is an additive manufacturing method with Mark forged Mark Two 3D-composite printer. The machinability studies were conducted for drilling operation through AWJM process with different abrasive mass flow rates, drilling diameters and traverse speeds. These drilling machinability process parameters were optimized through the design of experiments-Taguchi analysis followed by the analysis of variance(ANOVA) and validated through the Harmony Search Algorithm(HSA), Whale Optimization Algorithm(WOA) and Grey Wolf Optimization Algorithm(GWO). It was observed that minimum delamination and surface roughness of OGFHPC were optimized for AWJM at abrasive mass flow rates(450 g/min), drilling diameters(12 mm) and traverse speed rate(30 mm/min).展开更多
Continuous drive friction welding was employed to join the aeronautic aluminum alloy 2024.Parametric optimization and microstructural characterization were investigated.Results show that friction pressure is the most ...Continuous drive friction welding was employed to join the aeronautic aluminum alloy 2024.Parametric optimization and microstructural characterization were investigated.Results show that friction pressure is the most significant factor influencing the tensile strength of joints.To obtain a high joint efficiency,the combination of moderate friction pressure,less friction time and higher upset pressure is recommended.The optimized joint efficiency from Taguchi analysis reaches 92% of base metal.Under the optimized experimental condition,the interfacial peak temperature is calculated analytically in the range of 779-794 K,which is validated by experimental data.Fine recrystallized grains caused by the high temperature and plastic deformation are observed in the friction interface zone.The grain refinement is limited in the thermo-mechanically affected zone,where most of matrix grains are deformed severely.The extensive dissolution and limited re-precipitation of strengthening phases result in a lower microhardness in the friction interface zone than that in the thermo-mechanically affected zone.展开更多
Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are underutilized.Lignocellulosic biomass especially crop residues’potential to green energy development has b...Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are underutilized.Lignocellulosic biomass especially crop residues’potential to green energy development has been investigated.Material conditions as process variable was made a centerpiece of investigation in the present study since several parameters in the feedstock mixture come into interplay during pelletization.Moisture,binders,blending ratio,particle size,and principle feedstock material were the parameters of our interest in finding their effect on physical and thermochemical characteristics.It is also an endeavor to investigate low cost binder options in producing composite pellets of high quality.A Taguchi L9 orthogonal array experimental design was employed and Taguchi based Grey relational analysis was performed to determine the best combinatorial optimization of factor levels settings for producing best pellets.The optimal parameter level settings for pelletization was determined to be 3.18 mm wheat feedstock material blended with pine shavings at 60/40 ratio.An analysis of variance(ANOVA)was conducted to identify the contribution of each parameter.The magnitude of the significant impacts of parameters on performance characteristics were in the order of binder>blend ratio>grind>feedstock material.Results also showed that the physico-chemical characteristics of the pellets were concomitant with the proportion of ingredients or recipes in a blend.展开更多
The cellulosic bast fibers are recognized as a justifiable and biodegradable substitute for producing moderate strength polymer composite materials because of their characteristics of renewability,ecofriendliness,and ...The cellulosic bast fibers are recognized as a justifiable and biodegradable substitute for producing moderate strength polymer composite materials because of their characteristics of renewability,ecofriendliness,and higher specific strength.Hence the aim of this research work is to fabricate Himalayan bast fibers(Nettle fiber(NF)/bauhinia vahlii fiber(BF)) based mono/hybrid epoxy composites at varying weight percentage of 2-6 wt% and evaluate the physical(void fraction and water absorption),mechanical(tensile strength,flexural strength,hardness) and sliding wear properties of as-fabricated composites.The 6 wt% NBF reinforced composites exhibited higher mechanical properties as compared to NF and BF composites with tensile strength of 34.04 MPa,flexural strength of 42.45 MPa,and hardness of 37.01 Hv respectively.The influence of various control factors(sliding velocity,NF/BF/NBF contents,normal load and sliding distance) on specific sliding wear rate of composites was evaluated by Taguchi(three factors at three levels) experimental design and the percentage contribution of these selected parameters on sliding wear performance was examined by Analysis of variance(ANOVA).The sliding wear property of as-developed composites was found to be greatly influenced by sliding velocity and the wear resistance was observed to be improved with the NF/BF/NBF contents.The wear mechanism of the as-fabricated composites has been elucidated by scanning electron microscopy analysis.The research outcomes demonstrated that the hybridization of Bauhinia vahlii fiber with Nettle fiber led to improve the mechanical and wear properties of epoxy composites.展开更多
The aim of the research was to develop E-glass/jute fiber reinforced epoxy composites with an addition of Al<sub>2</sub>O<sub>3</sub> and bone powder by using hand layup technique and to compar...The aim of the research was to develop E-glass/jute fiber reinforced epoxy composites with an addition of Al<sub>2</sub>O<sub>3</sub> and bone powder by using hand layup technique and to compare tribological properties of these composites under similar test conditions. The wear experiments were designed according to Taguchi’s (L<sub>27</sub>) orthogonal array with three control variables such as sliding velocity, filler content and normal load. The results indicated that the normal load for Al<sub>2</sub>O<sub>3</sub> and filler content for bone powder emerged as the significant factors affecting specific wear rate of hybrid composites. An addition of 10 wt% of bone powder or Al<sub>2</sub>O<sub>3</sub> into E-glass/jute fiber reinforced epoxy composites increased the wear resistance considerably, and natural waste bone powder can be used instead of ceramic filler Al<sub>2</sub>O<sub>3</sub> in hybrid composites. After the analysis of control factors, an optimal factor setting has been suggested for specific wear rate and coefficient of friction. Further, the scanning electron microscopy (SEM) images for worn surfaces of hybrid composites were studied. Finally, a confirmation test was carried out to validate the results.展开更多
In this investigation,the effect of friction stir welding(FSW)parameters such as tool pin profiles,rotational speed and welding speed on the mechanical properties of tensile strength,hardness and impact energy of magn...In this investigation,the effect of friction stir welding(FSW)parameters such as tool pin profiles,rotational speed and welding speed on the mechanical properties of tensile strength,hardness and impact energy of magnesium alloy AZ31 was studied.The experiments were carried out as per Taguchi parametric design concepts and an L9 orthogonal array was used to study the influence of various combinations of process parameters.Statistical optimization technique,ANOVA,was used to determine the optimum levels and to find the significance of each process parameter.The results indicate that rotational speed(RS)and transverse speed(TS)are the most significant factors,followed by tool pin profile(PF),in deciding the mechanical properties of friction stir welded magnesium alloy.In addition,mathematical models were developed to establish relationship between different process variables and mechanical properties.展开更多
文摘The distribution–allocation problem is known as one of the most comprehensive strategic decisions.In real-world cases,it is impossible to solve a distribution–allocation problem completely in acceptable time.This forces the researchers to develop efficient heuristic techniques for the large-term operation of the whole supply chain.These techniques provide near optimal solution and are comparably fast particularly for large-scale test problems.This paper presents an integrated supply chain model which is flexible in the delivery path.As solution methodology,we apply a memetic algorithm with a novelty in population presentation.To identify the optimum operating condition of the proposed memetic algorithm,Taguchi method is adopted.In this study,four factors,namely population size,crossover rate,local search iteration and number of iteration,are considered.Determining the best level of the considered parameters is the outlook of this research.
文摘We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.
基金financially supported by the National Institute of Technology,Manipur,India
文摘The strength of the mould cavity in sand casting is very much significant to attain high-quality castings. Optimization of green sand process parameters plays a vital role in minimizing casting defects. In the present research work, the effect of process parameters such as AFS grain fineness number, water, molasses, bentonite, fly ash, and ramming, and their levels on the resultant mould properties were investigated and optimized using Taguchi based grey relational analysis. The Taguchi L18 orthogonal array and analysis of variance(ANOVA) were used. The quality characteristics viz., green compression strength, permeability, bulk density, mould hardness and shatter index of green sand mould were optimized using grey relational grade, based on the experiments designed using Taguchi's Design of Experiments. ANOVA analysis indicated that water content is the most influential parameter followed by bentonite, and degree of ramming that contributes to the quality characteristics. The results are confirmed by calculating confidence intervals, which lies within the interval limits. Finally, microstructure observations and X-ray diffraction analysis have been performed for the optimal sand parametric combination. Results show that presence of maximum amount of SiO_2, which might be the reason for enhancement of the physical properties of the sand.
文摘Compared with conventional manufacturing methods, the additive manufacturing technique enhances mechanical properties. The present investigation of additive manufacturing technique is focused on delamination studies of Onyx-Glass Fiber Hybrid Polymer Composite(OGFHPC) along with surface roughness properties during machining(drilling) of composites through abrasive water jet machining(AWJM). However, delamination is a major issue during machining of OGFHPC. In order to overcome these drawbacks, the fabrication of OGFHPC was carried out using fused deposition modeling(FDM) technology which is an additive manufacturing method with Mark forged Mark Two 3D-composite printer. The machinability studies were conducted for drilling operation through AWJM process with different abrasive mass flow rates, drilling diameters and traverse speeds. These drilling machinability process parameters were optimized through the design of experiments-Taguchi analysis followed by the analysis of variance(ANOVA) and validated through the Harmony Search Algorithm(HSA), Whale Optimization Algorithm(WOA) and Grey Wolf Optimization Algorithm(GWO). It was observed that minimum delamination and surface roughness of OGFHPC were optimized for AWJM at abrasive mass flow rates(450 g/min), drilling diameters(12 mm) and traverse speed rate(30 mm/min).
基金Project(51475196) supported by the National Natural Science Foundation of ChinaProject(2017ZX04004001) supported by the National Science and Technology Major Project on High-end Numerically Controlled Machine Tools and Basic Manufacturing Technology,China
文摘Continuous drive friction welding was employed to join the aeronautic aluminum alloy 2024.Parametric optimization and microstructural characterization were investigated.Results show that friction pressure is the most significant factor influencing the tensile strength of joints.To obtain a high joint efficiency,the combination of moderate friction pressure,less friction time and higher upset pressure is recommended.The optimized joint efficiency from Taguchi analysis reaches 92% of base metal.Under the optimized experimental condition,the interfacial peak temperature is calculated analytically in the range of 779-794 K,which is validated by experimental data.Fine recrystallized grains caused by the high temperature and plastic deformation are observed in the friction interface zone.The grain refinement is limited in the thermo-mechanically affected zone,where most of matrix grains are deformed severely.The extensive dissolution and limited re-precipitation of strengthening phases result in a lower microhardness in the friction interface zone than that in the thermo-mechanically affected zone.
文摘Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are underutilized.Lignocellulosic biomass especially crop residues’potential to green energy development has been investigated.Material conditions as process variable was made a centerpiece of investigation in the present study since several parameters in the feedstock mixture come into interplay during pelletization.Moisture,binders,blending ratio,particle size,and principle feedstock material were the parameters of our interest in finding their effect on physical and thermochemical characteristics.It is also an endeavor to investigate low cost binder options in producing composite pellets of high quality.A Taguchi L9 orthogonal array experimental design was employed and Taguchi based Grey relational analysis was performed to determine the best combinatorial optimization of factor levels settings for producing best pellets.The optimal parameter level settings for pelletization was determined to be 3.18 mm wheat feedstock material blended with pine shavings at 60/40 ratio.An analysis of variance(ANOVA)was conducted to identify the contribution of each parameter.The magnitude of the significant impacts of parameters on performance characteristics were in the order of binder>blend ratio>grind>feedstock material.Results also showed that the physico-chemical characteristics of the pellets were concomitant with the proportion of ingredients or recipes in a blend.
文摘The cellulosic bast fibers are recognized as a justifiable and biodegradable substitute for producing moderate strength polymer composite materials because of their characteristics of renewability,ecofriendliness,and higher specific strength.Hence the aim of this research work is to fabricate Himalayan bast fibers(Nettle fiber(NF)/bauhinia vahlii fiber(BF)) based mono/hybrid epoxy composites at varying weight percentage of 2-6 wt% and evaluate the physical(void fraction and water absorption),mechanical(tensile strength,flexural strength,hardness) and sliding wear properties of as-fabricated composites.The 6 wt% NBF reinforced composites exhibited higher mechanical properties as compared to NF and BF composites with tensile strength of 34.04 MPa,flexural strength of 42.45 MPa,and hardness of 37.01 Hv respectively.The influence of various control factors(sliding velocity,NF/BF/NBF contents,normal load and sliding distance) on specific sliding wear rate of composites was evaluated by Taguchi(three factors at three levels) experimental design and the percentage contribution of these selected parameters on sliding wear performance was examined by Analysis of variance(ANOVA).The sliding wear property of as-developed composites was found to be greatly influenced by sliding velocity and the wear resistance was observed to be improved with the NF/BF/NBF contents.The wear mechanism of the as-fabricated composites has been elucidated by scanning electron microscopy analysis.The research outcomes demonstrated that the hybridization of Bauhinia vahlii fiber with Nettle fiber led to improve the mechanical and wear properties of epoxy composites.
文摘The aim of the research was to develop E-glass/jute fiber reinforced epoxy composites with an addition of Al<sub>2</sub>O<sub>3</sub> and bone powder by using hand layup technique and to compare tribological properties of these composites under similar test conditions. The wear experiments were designed according to Taguchi’s (L<sub>27</sub>) orthogonal array with three control variables such as sliding velocity, filler content and normal load. The results indicated that the normal load for Al<sub>2</sub>O<sub>3</sub> and filler content for bone powder emerged as the significant factors affecting specific wear rate of hybrid composites. An addition of 10 wt% of bone powder or Al<sub>2</sub>O<sub>3</sub> into E-glass/jute fiber reinforced epoxy composites increased the wear resistance considerably, and natural waste bone powder can be used instead of ceramic filler Al<sub>2</sub>O<sub>3</sub> in hybrid composites. After the analysis of control factors, an optimal factor setting has been suggested for specific wear rate and coefficient of friction. Further, the scanning electron microscopy (SEM) images for worn surfaces of hybrid composites were studied. Finally, a confirmation test was carried out to validate the results.
文摘In this investigation,the effect of friction stir welding(FSW)parameters such as tool pin profiles,rotational speed and welding speed on the mechanical properties of tensile strength,hardness and impact energy of magnesium alloy AZ31 was studied.The experiments were carried out as per Taguchi parametric design concepts and an L9 orthogonal array was used to study the influence of various combinations of process parameters.Statistical optimization technique,ANOVA,was used to determine the optimum levels and to find the significance of each process parameter.The results indicate that rotational speed(RS)and transverse speed(TS)are the most significant factors,followed by tool pin profile(PF),in deciding the mechanical properties of friction stir welded magnesium alloy.In addition,mathematical models were developed to establish relationship between different process variables and mechanical properties.
