Md Helal Miah | Zhengzhou University (original) (raw)

Papers by Md Helal Miah

Materials Today: Proceedings, 2023

Regarding traditional fusion welding challenges, this research will illustrate the impact of the ... more Regarding traditional fusion welding challenges, this research will illustrate the impact of the combined welding parameter for the friction stir lap welding (FSLW) process for two Al-Mg-Si Al-alloy plate joints. Firstly, the oxide film on the surface of the workpiece was polished, and the surface was cleaned with absolute ethyl alcohol. Secondly, the sheets were fixed on a particular fixture. The ''FSW-3LM-4012" machine was used to employ the welding process. The stir tool rotated counterclockwise , and the ''welding direction" was parallel to the ''rolling-direction" of the base material. The width of the overlapped area of the upper and lower sheets was 50 mm. Finally, the result was optimized by cross-sectional analysis, fracture path analysis, microhardness analysis, and surface morphology analysis. It is evident that under the optimal value (1597.4 rpm-173.7 mm/min-0.124 mm) of the three applied welding parameters (WP), the heat input is the smallest, the grain size in the weld zone is the finest, and the effect of finegrain strengthening is most apparent. As a result, the microhardness is the best. The research has practical implications for the FSLW process in modern aerospace and automobile company.

AIP Conference Proceedings, 2023

The key characteristic of the aircraft assembly is to maintain assembly accuracy, and the measure... more The key characteristic of the aircraft assembly is to maintain assembly accuracy, and the measurement system employs a vital role to maintain the assembly characteristics. There are lots of measuring techniques, among them indoor global positioning system (iGPS) measuring is more efficient for aircraft assembly technology due to its high precision technique. In this research, the system configuration of the iGPS is discussed firstly. Then working principle and performance of the indoor GPS measurement system are reviewed. Based on the indoor global positioning measurement system and processes, the measurement error is analyzed qualitatively. At the same time, the application of indoor GPS measurement systems in aircraft assembly is discussed briefly. A systematic mechanism of indoor GPS has been introduced in this research that helps the aircraft assembly technician to use iGPS effectively. This research has practical value to determine the aircraft component/product position in the assembly line of the modern aviation industry.

Materials Today: Proceedings, 2022

Recently ''Friction Stir Welding'' (FSW) has been one of the significant inventions in the weldin... more Recently ''Friction Stir Welding'' (FSW) has been one of the significant inventions in the welding and manufacturing world. But in FSW or any friction stir techniques, appearing ''Keyholes" became a common issue. The retraction of non-consumable rotational pin tools mainly causes the ''Keyhole.'' This research illustrates a novel approach called ''Friction Stir Additive Manufacturing" (FSAM) is used to repair the ''Keyhole.'' The hole was successfully repaired by using a series of pin-less rotational tools. In this research, aluminum alloy 7N01 was chosen as the ''Base Material" (BM), and the ''Keyhole'' in this alloy was investigated. Many microstructural properties of the joint were observed. Microstructures of the joint, especially the in the ''Filling Zone" FZ, were observed. The result shows that it was repaired successfully without any defect appearing in the FZ of the joint employing the transverse velocity of 2 mm/min and ''Rotational Speed" (RS) of 1600 rpm. The FZs are analyzed by equiaxed grains. At the transverse velocity of 2 mm/min and the RS of 1600 rpm, the ''Tensile Strength" and ''Elongation" of the joint reach the maximum values of 311.5 MPa and 7.6 %, which indicate up to 82.2 % and 96 % of defect-free FSW joint, respectively. In addition, the fracture surface morphology shows various dimples, indicating good mechanical properties with typical ductile fracture.

Materials Today: Proceedings, 2022

Regarding the challenges of welding for aluminum alloy, this research illustrates the influence o... more Regarding the challenges of welding for aluminum alloy, this research illustrates the influence of convex shoulder on mechanical and tribological behavior of friction stir lap welding of aircraft assembly technology. This research employs a spiral whirling needle convex shoulder, and the friction diffusion-welding test is carried out with 2024-T4 aluminum alloy sheets. Then the influence of the numbers of vortexlike needle convex shoulders on the cross-section morphology, material flow behavior, and mechanical properties are compared and analyzed. The experimental results show that there is no obvious bending phenomenon at the lapping interface under the action of a vortex-shaped stirring pin, and increasing the number of vortex-shaped structures is beneficial to increase the cross-sectional width of the nugget area. When the four vortex-shaped mixing needles are adopted, the effective lap width and fracture load of the lap joint with tensile fracture mode are greater than those with six vortex structures, respectively; the values are 11.74 mm and 17531.83 N.

Materials Today: Proceedings, 2022

Large-diameter hole drilling for Carbon-Fibre-Reinforced-Polymer (CFRP) is challenging because of... more Large-diameter hole drilling for Carbon-Fibre-Reinforced-Polymer (CFRP) is challenging because of its non-homogeneity and anisotropic features. This research will illustrate the hand-laminated and unidirectional CFRP based on three-hole making strategies for helical milling, large hole and pilot hole drilling. In this article, CFRP analyzes and optimizes axial cutting force and Delamination Factor (DF) based on experimental data collected at different FR (Feed Rate). CFRP's large diameter hole quality analysis includes cutting speed (Rotational Tool Speed) and scanning electron microscopy (SEM) analysis of helical milling, pilot hole and large hole drilling. A comparative study between large hole diameter, pilot hole drilling, and helical milling of CFRP was also conducted to discover the better technology for hole calibration quality by analyzing Machining Force (MF) and DF. According to experimental tests of CFRP laminates, the MF is proportional to the FR. Compared to helical milling, pilot hole drilling with proper cutting parameters can create superior quality holes. As a result, it is recommended that pilot hole drilling be done at a low feed rate and a high rotational tool speed for optimum hole quality. The hole calibration was analyzed to distinguish the cutting parameters (Cutting Speed, FR, and MF) to reduce DF and improve hole quality. Low FR was necessary for CFRP high-speed drilling because delamination at the hole exit was a concern.

Environmental Monitoring and Assessment, 2022

them contributes more to the destruction of the environment. With the current trend of population... more them contributes more to the destruction of the environment. With the current trend of population growth followed by the construction of companies to suit their wants, such a situation may worsen. Hazardous gases, dust particles, or liquid effluents are the waste products emitted from industrial sources. These discharges are full of harmful chemicals that pollute aquatic ecosystems, disrupt the local biota, and eventually harm living things and associated flora and animals. As a result, studies were conducted, including the physicochemical characterization of sugar refineries, distilleries, and other rivers that receive such effluents. These characteristics of subsurface water were also taken into consideration throughout the inquiry. This research will be anticipated to offer proper preventive methods for preserving the purity of the Bangladeshi rivers.

Aircraft Engineering and Aerospace Technology, 2022

Purpose-Regarding the assembly of the fuselage panel, this paper aims to illustrate a design of p... more Purpose-Regarding the assembly of the fuselage panel, this paper aims to illustrate a design of pre-assembly tooling of the fuselage panel for the automatic drilling riveting machine. This new prototype of pre-assembly tooling can be used for different types and sizes of fuselage panels. Also, apply to the automated drilling and riveting machine of the fuselage panels. Design/methodology/approach-Based on the different structures of the fuselage panel, the position of the preassembly tooling components, location of the clamp and position of the fuselage panel are determined. After that, the overall structure of the preassembly tooling is designed, including the movable frame and the cardboard. The cardboard positioning module and the clamping module formulate a detailed design scheme of preassembly tooling for the fuselage panel. The structure of the pre-assembled tooling is optimized by static analysis. The result of the overall design is optimized by using MATLAB and CATIA-V5 software, and the results meet the condition of the design requirements. Findings-The traditional assembly process of the fuselage is to install the fuselage panel on the preassembly tooling for positioning the hole and then install it on the automated drilling and riveting tooling for secondary tooling. Secondary tooling can consume assembly errors of the fuselage panel. The new prototype of flexible tooling design for the fuselage panel not only avoids the secondary tooling error of the fuselage panel but also meets the preassembly of different types of fuselage panels. Research limitations/implications-The further development of the flexible tooling design of the fuselage panel is to reduce the error of sliding tooling due to friction of the sliding components. Because if the assembly cycle is increased, the sliding parts will lose material due to corrosion. As a result, the repeated friction force is the root cause of the positioning error of sliding parts. Therefore, it is necessary to engage less corrosive material. Also, the lubricant may be used to reduce the corrosion in minimizing the positioning error of the sliding tool components. In addition, it is important to calculate the number of assembly cycles for efficient fuselage panel assembly. Originality/value-According to the structure and assembly process characteristics of the fuselage panel, the fuselage panel preassembly tooling can optimize the assembly process of the fuselage panel and have certain practical application values.

American Journal of Aerospace Engineering. , 2022

The main purpose of the digital aircraft assembly process is to ensure the high assembly accuracy... more The main purpose of the digital aircraft assembly process is to ensure the high assembly accuracy of aircraft products, flexibility and reduce the assembly time. Also, reduce the assembly and manufacture error of tooling (Jig/Fixture) design for particular aircraft products. Generally, the aircraft product assembly process is complex, and it performs through the assembly and disassembly process. Regarding the complexity of the aircraft product assembly process, this research illustrates the systematic analysis of the simulation and visualization technology for the aircraft assembly process. This research introduces key technologies and solutions to realize the aircraft's assembly process visualization system. Then assembly simulation environment is implemented based on virtual reality modelling language (VRML), network, assembly process simulation, and visualization of assembly process documents. The digital aircraft assembly process technology has been divided into simulation and visualization systems in this research. The simulation process includes manufacturing factors, assembly objects, assembly sites, process equipment, tools, and devices. The visualization system visually processes the assembly simulation results and then outputs the processed results in the workshop workplace. It includes the related simulation results and adds necessary text technology to make it easier to understand the concept using visualization techniques to process the results. The research has practical value in the modern aircraft industry to propose an aircraft product simulation process based on computer-aided 3D design.

Emerald Publishing Limited, 2021

Purpose-The effective and efficient implementation of daily work activities necessitates tacit kn... more Purpose-The effective and efficient implementation of daily work activities necessitates tacit knowledge sharing, boosting firm productivity. However, the link between tacit knowledge sharing within a company and its effects on organizational performance is unclear, so the purpose of this study is to examine the impact of sharing tacit knowledge on the success of a company. Design/methodology/approach-Construction managers and senior managers were the study's target participants. The correlation matrix was used to assess the significant correlation between study frameworks and the statistical approach of multiple regression was also used to test the hypotheses using statistical package for social sciences (SPSS) v.26. Findings-The findings suggest that companies will be more willing and capable of making decisions based on experience when knowledge systems are used successfully. Furthermore, new organizational knowledge and particular evaluation procedures, such as anxiety and conflict resolution preparation, personal relationship and training improvement, mediation and task clarity, are explained, which can aid in success. Originality/value-The study contributes to construction companies' perception of knowledge sharing and recommends organizations to build capacity to encourage, improve engagement and review to maintain the dissemination of knowledge.

Emerald Publishing Limited, 2022

Purpose-"V-bending" is the most commonly used bending process in which the sheet metal is pressed... more Purpose-"V-bending" is the most commonly used bending process in which the sheet metal is pressed into a "V-shaped" die using a "V-shaped" punch to form a required angular bend. When the punch is removed after the operation, because of elastic recovery, the bent angle varies. This shape discrepancy is known as spring back which causes problems in the assembly of the component in the modern aerospace industry. Regarding the optimization of spring-back accuracy, this research will illustrate the laws of the transition area (TA) of the nondeformation area (NDA) during the 90°"V-shape" bending process. Design/methodology/approach-According to the traditional "V-bending" process to optimize the spring-back accuracy, the bent sheets are divided into deformation area (DA) and NDA. For this reason, the traditional "V-bending" process may prolong error to optimize the spring-back accuracy because NDA has a certain amount of deformation, which the researcher always avoids. Firstly, bent sheets are divided into three parts in this research: DA, TA and NDA to avoid the distortion error in TA that are not considered in the NDA in traditional theory. Then, the stress and strain in the DA and TA were discussed during theoretical derivation and some hypotheses were proposed. In this research, the interval, position and distortion degree of the TA of the bending sheet are used by finite element analysis. Finally, V-shape bending tests for aluminum alloy at room temperature are used and labeled all the work pieces' TAs to realize the deformation amount in the TA. Findings-The bending radius does not affect the range of the TA, it only changes the position of TA in the bending sheet. It is evident that the laws of TA were explored in the width direction and gradually changed from the inner layer to the outer layer based on the ratio of width and thickness of the bending plate/sheet. Originality/value-In the modern aerospace industry, aircraft manufacturing technology must maintain high accuracy. This research has practical value in the 90°"V-shape" bending of metal sheets and the development of its spring-back accuracy.

This research compounded nanoparticles with epoxy resin, measured the thermal conductivity (TC) e... more This research compounded nanoparticles with epoxy resin, measured the thermal conductivity (TC) enhancement, characterized the morphology of these composites, and investigated the mechanical properties (MP) of resulting composite films. The resulting in unique physiochemical properties originating from the mixed behavioral properties of the nanoparticles and epoxy into one unity by employed Boron Nitride (BN) as a secondary filler into the epoxy matrix (EM). BN is increasingly being employed as a secondary filler to enrich the characteristics of epoxy resin. Also, solving some of its drawbacks such as brittleness and low TC. This research analyzed epoxy-matrix composites applying BN as filler and J2000 hardener. Composites containing from 0.5 wt% up to 10 wt% of filler were fabricated by solution mixing. The filler was effectively dispersed within the matrix using the sonication method. The specimens were subjected to TC calculations, as well as morphological analysis and a tensile strength test. TC of the pure resin signifies approximately 132.3% increase concerning the composite containing 10 wt% of BN. Sonication evidences to be a competent technique in exfoliating the BN and assisting its dispersion in the EM. Furthermore, the addition of BN enhanced the host matrix's young's modulus and tensile strength, as well as improved ductility (due to the usage of the J2000 hardener), resulting in a flexible composite film.

Journal of Positive School Psychology , 2022

According to the basic principle of law, anyone should be considered innocent in law before findi... more According to the basic principle of law, anyone should be considered innocent in law before finding himself guilty by the court. The principle of presumption of innocence is mainly manifested in two aspects: firstly, the accusing party takes the burden of proof. Secondly, it protects the fundamental rights of citizens, especially those suspected of crimes rights of persons and defendants. This research will explore how the state initiates criminal prosecution based on criminal suspicion regarding the basic principle of presumption of innocence. Also, this article illustrates the difference between criminal suspicion and crime and criminal facts, conducts a conceptual analysis of criminal suspicion, and discusses the classification and proof of crime suspicion to describe the three main types of criminal suspicion manifested in procedural law. Firstly, the concept of a criminal suspect has been defined to understand the crime that endangers society and should be punished according to the law. Secondly, the identification and proof of criminal suspect are investigated based on investigative, procedural organs and whether the presumptions about the crime and the perpetrator are correct. Finally, the effect of the criminal suspect in the procedural law has been observed for a free citizen turns from a native person to a criminal is that he has a criminal suspicion, and the investigation and prosecution agency suspects that he has committed a crime. The research has practical implications in the principle of presumption of innocence. It effectively protects the lawsuits of criminal suspects and defendants only by clarifying the difference between criminal suspects and criminal facts but also criminal suspects and criminals at the legislative level and in judicial practice.

SAE International, 2022

his paper will focus on the root facture problem of carbon fibre reinforced polymers (CFRP) mater... more his paper will focus on the root facture problem of carbon fibre reinforced polymers (CFRP) material of aircraft winglets through ABAQUS simulation analysis regarding the aircraft takeoff and landing from high altitude at the constant and low-temperature experimental analysis and topography analysis. The innovative purpose of this paper is to identify the critical failure stress of the cantilever bending of unidirectional and orthogonal, embedding carbon nanotube reinforcement, and exploring the embedded carbon nanotube regarding the enhancement effect of CFRP aircraft winglet. First of all, the analysis of the force state of the aircraft winglet, the unidirectional and orthogonal CFRP aircraft winglet at normal temperature, and low-temperature cycling is established based on the principle of classic laminates and statics. The wing cantilever bending critical failure stress mechanics model provides a theoretical basis for the influence of low-temperature cycles on aircraft winglets. Secondly, verifying the correctness of the above-mentioned mechanical model, the CFRP aircraft winglet was studied through bending stress analysis, stress-displacement curve analysis, and sample topography analysis. Finally, the equipment for preparing embedded carbon nanotubes CFRP composite material was designed to ensure the accuracy of the test piece and explored the effect of embedded carbon nanotubes on the CFRP aircraft winglet. The main reason for the weakening of the winglet cantilever anti-bending strength is the fibre. During the lowtemperature cycle, the residual stress generated by the aircraft winglet fiber's repeated damp and heat deformation is too weak to increase the wing's cantilever bending failure critical stress. The enhanced result of the cantilever anti-bending ability and the microscopic mechanism of action provides the basis of the carbon nanotube reinforcement medium to the CFRP aircraft winglet development.

A combined heat source model (HSM) is a new technology to resolve the welding problem of aluminum... more A combined heat source model (HSM) is a new technology to resolve the welding problem of aluminum alloy in the friction stir welding (FSW) process. It authenticates advantage is solid-phase welding technology for magnesium, aluminum, and other low melting point alloy welding. Temperature field analysis is the prerequisite for improving the welding quality, welding metallurgy, and mechanical analysis. An accurate grasp of the temperature field distribution on the FSW process plays a vital role. In this research, the temperature field of FSW for 6005 aluminum alloy is simulated and analyzed by SYSWELD software. Then the simulation results were verified by experimental results. First of all, the finite element simulation and theoretical analysis were carried out for the FSW process. Then finite element model was established by using the SYSWELD software. And the temperature field of the FSW process was established by grid partitioning, HSM setting, and subsequent observation. The numerical simulation method is used to analyze the temperature field of the FSW process. Finally, the simulation results are verified and calibrated by the thermocouple temperature test. The influence of different welding parameters (Welding Speed and Rotational Speed) on the temperature field is evaluated by the thermal field curves analysis and some particular nodes analysis of the target area.

This research study investigates the effect of unsaturated polyester toughening on mechanical and... more This research study investigates the effect of unsaturated polyester toughening on mechanical and morphological characteristics of glass fibre reinforced epoxy composites. Here, a polyester/epoxy matrix blend was prepared using an ultrasonicator. Three different epoxy/polyester blended composite specimens (75:25, 50:50 and 25:75) were prepared using the vacuum bag moulding process. The composite samples were evaluated for mechanical properties such as tensile, compression, shear, hardness and impact loadings. The mode-I fracture test is also conducted using a DCB specimen to characterize the inter-laminar fracture behaviour of blended matrix composite specimens. The evaluated results were compared with neat polyester and epoxy composites. The addition of polyester in the epoxy increases the hardness as well as fracture toughness, and it was found to be higher than the neat matrix specimens. But the tensile and compressive response of the blended matrix composites is intermediate between the neat epoxy and polyester composites. The mechanical response of the blended matrix composites degrades when the proportion of the polyester in the blend increases.

Emerald Publishing Limited, 2021

Purpose-This paper aims to illustrate the tolerance optimization method based on the assembly acc... more Purpose-This paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product. Design/methodology/approach-A tolerance optimization method is an excellent way to perform product assembly performance. The tolerance optimization method is adapted to the process analysis of the hatch and skin of an aircraft. In this paper, the tolerance optimization techniques are applied to the tolerance allocation for step difference analysis (example: step difference between aircraft cabin door and fuselage outer skin). First, a mathematical model is described to understand the relationship between manufacturing cost and tolerance cost. Second, the penalty function method is applied to form a new equation for tolerance optimization. Finally, MATLAB software is used to calculate 170 loops iteration to understand the efficiency of the new equation for tolerance optimization. Findings-The tolerance optimization method is based on the assembly accuracy constrain, machinery constrain and the cost of production of the assembly product. The main finding of this paper is the lowest assembly and lowest production costs that met the product tolerance specification. Research limitations/implications-This paper illustrated an efficient method of tolerance allocation for products assembly. After 170 loops iterations, it founds that the results very close to the original required tolerance. But it can easily say that the different number of loops iterations may have a different result. But optimization result must be approximate to the original tolerance requirements. Practical implications-It is evident from Table 4 that the tolerance of the closed loop is 1.3999 after the tolerance distribution is completed, which is less than and very close to the original tolerance of 1.40; the machining precision constraint of the outer skin of the cabin door and the fuselage is satisfied, and the assembly precision constraint of the closed loop is satisfied. Originality/value-The research may support further research studies to minimize cost tolerance allocation using tolerance cost optimization techniques, which must meet the given constrain accuracy for assembly products.

Materials Today: Proceedings, 2023

Regarding traditional fusion welding challenges, this research will illustrate the impact of the ... more Regarding traditional fusion welding challenges, this research will illustrate the impact of the combined welding parameter for the friction stir lap welding (FSLW) process for two Al-Mg-Si Al-alloy plate joints. Firstly, the oxide film on the surface of the workpiece was polished, and the surface was cleaned with absolute ethyl alcohol. Secondly, the sheets were fixed on a particular fixture. The ''FSW-3LM-4012" machine was used to employ the welding process. The stir tool rotated counterclockwise , and the ''welding direction" was parallel to the ''rolling-direction" of the base material. The width of the overlapped area of the upper and lower sheets was 50 mm. Finally, the result was optimized by cross-sectional analysis, fracture path analysis, microhardness analysis, and surface morphology analysis. It is evident that under the optimal value (1597.4 rpm-173.7 mm/min-0.124 mm) of the three applied welding parameters (WP), the heat input is the smallest, the grain size in the weld zone is the finest, and the effect of finegrain strengthening is most apparent. As a result, the microhardness is the best. The research has practical implications for the FSLW process in modern aerospace and automobile company.

AIP Conference Proceedings, 2023

The key characteristic of the aircraft assembly is to maintain assembly accuracy, and the measure... more The key characteristic of the aircraft assembly is to maintain assembly accuracy, and the measurement system employs a vital role to maintain the assembly characteristics. There are lots of measuring techniques, among them indoor global positioning system (iGPS) measuring is more efficient for aircraft assembly technology due to its high precision technique. In this research, the system configuration of the iGPS is discussed firstly. Then working principle and performance of the indoor GPS measurement system are reviewed. Based on the indoor global positioning measurement system and processes, the measurement error is analyzed qualitatively. At the same time, the application of indoor GPS measurement systems in aircraft assembly is discussed briefly. A systematic mechanism of indoor GPS has been introduced in this research that helps the aircraft assembly technician to use iGPS effectively. This research has practical value to determine the aircraft component/product position in the assembly line of the modern aviation industry.

Materials Today: Proceedings, 2022

Recently ''Friction Stir Welding'' (FSW) has been one of the significant inventions in the weldin... more Recently ''Friction Stir Welding'' (FSW) has been one of the significant inventions in the welding and manufacturing world. But in FSW or any friction stir techniques, appearing ''Keyholes" became a common issue. The retraction of non-consumable rotational pin tools mainly causes the ''Keyhole.'' This research illustrates a novel approach called ''Friction Stir Additive Manufacturing" (FSAM) is used to repair the ''Keyhole.'' The hole was successfully repaired by using a series of pin-less rotational tools. In this research, aluminum alloy 7N01 was chosen as the ''Base Material" (BM), and the ''Keyhole'' in this alloy was investigated. Many microstructural properties of the joint were observed. Microstructures of the joint, especially the in the ''Filling Zone" FZ, were observed. The result shows that it was repaired successfully without any defect appearing in the FZ of the joint employing the transverse velocity of 2 mm/min and ''Rotational Speed" (RS) of 1600 rpm. The FZs are analyzed by equiaxed grains. At the transverse velocity of 2 mm/min and the RS of 1600 rpm, the ''Tensile Strength" and ''Elongation" of the joint reach the maximum values of 311.5 MPa and 7.6 %, which indicate up to 82.2 % and 96 % of defect-free FSW joint, respectively. In addition, the fracture surface morphology shows various dimples, indicating good mechanical properties with typical ductile fracture.

Materials Today: Proceedings, 2022

Regarding the challenges of welding for aluminum alloy, this research illustrates the influence o... more Regarding the challenges of welding for aluminum alloy, this research illustrates the influence of convex shoulder on mechanical and tribological behavior of friction stir lap welding of aircraft assembly technology. This research employs a spiral whirling needle convex shoulder, and the friction diffusion-welding test is carried out with 2024-T4 aluminum alloy sheets. Then the influence of the numbers of vortexlike needle convex shoulders on the cross-section morphology, material flow behavior, and mechanical properties are compared and analyzed. The experimental results show that there is no obvious bending phenomenon at the lapping interface under the action of a vortex-shaped stirring pin, and increasing the number of vortex-shaped structures is beneficial to increase the cross-sectional width of the nugget area. When the four vortex-shaped mixing needles are adopted, the effective lap width and fracture load of the lap joint with tensile fracture mode are greater than those with six vortex structures, respectively; the values are 11.74 mm and 17531.83 N.

Materials Today: Proceedings, 2022

Large-diameter hole drilling for Carbon-Fibre-Reinforced-Polymer (CFRP) is challenging because of... more Large-diameter hole drilling for Carbon-Fibre-Reinforced-Polymer (CFRP) is challenging because of its non-homogeneity and anisotropic features. This research will illustrate the hand-laminated and unidirectional CFRP based on three-hole making strategies for helical milling, large hole and pilot hole drilling. In this article, CFRP analyzes and optimizes axial cutting force and Delamination Factor (DF) based on experimental data collected at different FR (Feed Rate). CFRP's large diameter hole quality analysis includes cutting speed (Rotational Tool Speed) and scanning electron microscopy (SEM) analysis of helical milling, pilot hole and large hole drilling. A comparative study between large hole diameter, pilot hole drilling, and helical milling of CFRP was also conducted to discover the better technology for hole calibration quality by analyzing Machining Force (MF) and DF. According to experimental tests of CFRP laminates, the MF is proportional to the FR. Compared to helical milling, pilot hole drilling with proper cutting parameters can create superior quality holes. As a result, it is recommended that pilot hole drilling be done at a low feed rate and a high rotational tool speed for optimum hole quality. The hole calibration was analyzed to distinguish the cutting parameters (Cutting Speed, FR, and MF) to reduce DF and improve hole quality. Low FR was necessary for CFRP high-speed drilling because delamination at the hole exit was a concern.

Environmental Monitoring and Assessment, 2022

them contributes more to the destruction of the environment. With the current trend of population... more them contributes more to the destruction of the environment. With the current trend of population growth followed by the construction of companies to suit their wants, such a situation may worsen. Hazardous gases, dust particles, or liquid effluents are the waste products emitted from industrial sources. These discharges are full of harmful chemicals that pollute aquatic ecosystems, disrupt the local biota, and eventually harm living things and associated flora and animals. As a result, studies were conducted, including the physicochemical characterization of sugar refineries, distilleries, and other rivers that receive such effluents. These characteristics of subsurface water were also taken into consideration throughout the inquiry. This research will be anticipated to offer proper preventive methods for preserving the purity of the Bangladeshi rivers.

Aircraft Engineering and Aerospace Technology, 2022

Purpose-Regarding the assembly of the fuselage panel, this paper aims to illustrate a design of p... more Purpose-Regarding the assembly of the fuselage panel, this paper aims to illustrate a design of pre-assembly tooling of the fuselage panel for the automatic drilling riveting machine. This new prototype of pre-assembly tooling can be used for different types and sizes of fuselage panels. Also, apply to the automated drilling and riveting machine of the fuselage panels. Design/methodology/approach-Based on the different structures of the fuselage panel, the position of the preassembly tooling components, location of the clamp and position of the fuselage panel are determined. After that, the overall structure of the preassembly tooling is designed, including the movable frame and the cardboard. The cardboard positioning module and the clamping module formulate a detailed design scheme of preassembly tooling for the fuselage panel. The structure of the pre-assembled tooling is optimized by static analysis. The result of the overall design is optimized by using MATLAB and CATIA-V5 software, and the results meet the condition of the design requirements. Findings-The traditional assembly process of the fuselage is to install the fuselage panel on the preassembly tooling for positioning the hole and then install it on the automated drilling and riveting tooling for secondary tooling. Secondary tooling can consume assembly errors of the fuselage panel. The new prototype of flexible tooling design for the fuselage panel not only avoids the secondary tooling error of the fuselage panel but also meets the preassembly of different types of fuselage panels. Research limitations/implications-The further development of the flexible tooling design of the fuselage panel is to reduce the error of sliding tooling due to friction of the sliding components. Because if the assembly cycle is increased, the sliding parts will lose material due to corrosion. As a result, the repeated friction force is the root cause of the positioning error of sliding parts. Therefore, it is necessary to engage less corrosive material. Also, the lubricant may be used to reduce the corrosion in minimizing the positioning error of the sliding tool components. In addition, it is important to calculate the number of assembly cycles for efficient fuselage panel assembly. Originality/value-According to the structure and assembly process characteristics of the fuselage panel, the fuselage panel preassembly tooling can optimize the assembly process of the fuselage panel and have certain practical application values.

American Journal of Aerospace Engineering. , 2022

The main purpose of the digital aircraft assembly process is to ensure the high assembly accuracy... more The main purpose of the digital aircraft assembly process is to ensure the high assembly accuracy of aircraft products, flexibility and reduce the assembly time. Also, reduce the assembly and manufacture error of tooling (Jig/Fixture) design for particular aircraft products. Generally, the aircraft product assembly process is complex, and it performs through the assembly and disassembly process. Regarding the complexity of the aircraft product assembly process, this research illustrates the systematic analysis of the simulation and visualization technology for the aircraft assembly process. This research introduces key technologies and solutions to realize the aircraft's assembly process visualization system. Then assembly simulation environment is implemented based on virtual reality modelling language (VRML), network, assembly process simulation, and visualization of assembly process documents. The digital aircraft assembly process technology has been divided into simulation and visualization systems in this research. The simulation process includes manufacturing factors, assembly objects, assembly sites, process equipment, tools, and devices. The visualization system visually processes the assembly simulation results and then outputs the processed results in the workshop workplace. It includes the related simulation results and adds necessary text technology to make it easier to understand the concept using visualization techniques to process the results. The research has practical value in the modern aircraft industry to propose an aircraft product simulation process based on computer-aided 3D design.

Emerald Publishing Limited, 2021

Purpose-The effective and efficient implementation of daily work activities necessitates tacit kn... more Purpose-The effective and efficient implementation of daily work activities necessitates tacit knowledge sharing, boosting firm productivity. However, the link between tacit knowledge sharing within a company and its effects on organizational performance is unclear, so the purpose of this study is to examine the impact of sharing tacit knowledge on the success of a company. Design/methodology/approach-Construction managers and senior managers were the study's target participants. The correlation matrix was used to assess the significant correlation between study frameworks and the statistical approach of multiple regression was also used to test the hypotheses using statistical package for social sciences (SPSS) v.26. Findings-The findings suggest that companies will be more willing and capable of making decisions based on experience when knowledge systems are used successfully. Furthermore, new organizational knowledge and particular evaluation procedures, such as anxiety and conflict resolution preparation, personal relationship and training improvement, mediation and task clarity, are explained, which can aid in success. Originality/value-The study contributes to construction companies' perception of knowledge sharing and recommends organizations to build capacity to encourage, improve engagement and review to maintain the dissemination of knowledge.

Emerald Publishing Limited, 2022

Purpose-"V-bending" is the most commonly used bending process in which the sheet metal is pressed... more Purpose-"V-bending" is the most commonly used bending process in which the sheet metal is pressed into a "V-shaped" die using a "V-shaped" punch to form a required angular bend. When the punch is removed after the operation, because of elastic recovery, the bent angle varies. This shape discrepancy is known as spring back which causes problems in the assembly of the component in the modern aerospace industry. Regarding the optimization of spring-back accuracy, this research will illustrate the laws of the transition area (TA) of the nondeformation area (NDA) during the 90°"V-shape" bending process. Design/methodology/approach-According to the traditional "V-bending" process to optimize the spring-back accuracy, the bent sheets are divided into deformation area (DA) and NDA. For this reason, the traditional "V-bending" process may prolong error to optimize the spring-back accuracy because NDA has a certain amount of deformation, which the researcher always avoids. Firstly, bent sheets are divided into three parts in this research: DA, TA and NDA to avoid the distortion error in TA that are not considered in the NDA in traditional theory. Then, the stress and strain in the DA and TA were discussed during theoretical derivation and some hypotheses were proposed. In this research, the interval, position and distortion degree of the TA of the bending sheet are used by finite element analysis. Finally, V-shape bending tests for aluminum alloy at room temperature are used and labeled all the work pieces' TAs to realize the deformation amount in the TA. Findings-The bending radius does not affect the range of the TA, it only changes the position of TA in the bending sheet. It is evident that the laws of TA were explored in the width direction and gradually changed from the inner layer to the outer layer based on the ratio of width and thickness of the bending plate/sheet. Originality/value-In the modern aerospace industry, aircraft manufacturing technology must maintain high accuracy. This research has practical value in the 90°"V-shape" bending of metal sheets and the development of its spring-back accuracy.

This research compounded nanoparticles with epoxy resin, measured the thermal conductivity (TC) e... more This research compounded nanoparticles with epoxy resin, measured the thermal conductivity (TC) enhancement, characterized the morphology of these composites, and investigated the mechanical properties (MP) of resulting composite films. The resulting in unique physiochemical properties originating from the mixed behavioral properties of the nanoparticles and epoxy into one unity by employed Boron Nitride (BN) as a secondary filler into the epoxy matrix (EM). BN is increasingly being employed as a secondary filler to enrich the characteristics of epoxy resin. Also, solving some of its drawbacks such as brittleness and low TC. This research analyzed epoxy-matrix composites applying BN as filler and J2000 hardener. Composites containing from 0.5 wt% up to 10 wt% of filler were fabricated by solution mixing. The filler was effectively dispersed within the matrix using the sonication method. The specimens were subjected to TC calculations, as well as morphological analysis and a tensile strength test. TC of the pure resin signifies approximately 132.3% increase concerning the composite containing 10 wt% of BN. Sonication evidences to be a competent technique in exfoliating the BN and assisting its dispersion in the EM. Furthermore, the addition of BN enhanced the host matrix's young's modulus and tensile strength, as well as improved ductility (due to the usage of the J2000 hardener), resulting in a flexible composite film.

Journal of Positive School Psychology , 2022

According to the basic principle of law, anyone should be considered innocent in law before findi... more According to the basic principle of law, anyone should be considered innocent in law before finding himself guilty by the court. The principle of presumption of innocence is mainly manifested in two aspects: firstly, the accusing party takes the burden of proof. Secondly, it protects the fundamental rights of citizens, especially those suspected of crimes rights of persons and defendants. This research will explore how the state initiates criminal prosecution based on criminal suspicion regarding the basic principle of presumption of innocence. Also, this article illustrates the difference between criminal suspicion and crime and criminal facts, conducts a conceptual analysis of criminal suspicion, and discusses the classification and proof of crime suspicion to describe the three main types of criminal suspicion manifested in procedural law. Firstly, the concept of a criminal suspect has been defined to understand the crime that endangers society and should be punished according to the law. Secondly, the identification and proof of criminal suspect are investigated based on investigative, procedural organs and whether the presumptions about the crime and the perpetrator are correct. Finally, the effect of the criminal suspect in the procedural law has been observed for a free citizen turns from a native person to a criminal is that he has a criminal suspicion, and the investigation and prosecution agency suspects that he has committed a crime. The research has practical implications in the principle of presumption of innocence. It effectively protects the lawsuits of criminal suspects and defendants only by clarifying the difference between criminal suspects and criminal facts but also criminal suspects and criminals at the legislative level and in judicial practice.

SAE International, 2022

his paper will focus on the root facture problem of carbon fibre reinforced polymers (CFRP) mater... more his paper will focus on the root facture problem of carbon fibre reinforced polymers (CFRP) material of aircraft winglets through ABAQUS simulation analysis regarding the aircraft takeoff and landing from high altitude at the constant and low-temperature experimental analysis and topography analysis. The innovative purpose of this paper is to identify the critical failure stress of the cantilever bending of unidirectional and orthogonal, embedding carbon nanotube reinforcement, and exploring the embedded carbon nanotube regarding the enhancement effect of CFRP aircraft winglet. First of all, the analysis of the force state of the aircraft winglet, the unidirectional and orthogonal CFRP aircraft winglet at normal temperature, and low-temperature cycling is established based on the principle of classic laminates and statics. The wing cantilever bending critical failure stress mechanics model provides a theoretical basis for the influence of low-temperature cycles on aircraft winglets. Secondly, verifying the correctness of the above-mentioned mechanical model, the CFRP aircraft winglet was studied through bending stress analysis, stress-displacement curve analysis, and sample topography analysis. Finally, the equipment for preparing embedded carbon nanotubes CFRP composite material was designed to ensure the accuracy of the test piece and explored the effect of embedded carbon nanotubes on the CFRP aircraft winglet. The main reason for the weakening of the winglet cantilever anti-bending strength is the fibre. During the lowtemperature cycle, the residual stress generated by the aircraft winglet fiber's repeated damp and heat deformation is too weak to increase the wing's cantilever bending failure critical stress. The enhanced result of the cantilever anti-bending ability and the microscopic mechanism of action provides the basis of the carbon nanotube reinforcement medium to the CFRP aircraft winglet development.

A combined heat source model (HSM) is a new technology to resolve the welding problem of aluminum... more A combined heat source model (HSM) is a new technology to resolve the welding problem of aluminum alloy in the friction stir welding (FSW) process. It authenticates advantage is solid-phase welding technology for magnesium, aluminum, and other low melting point alloy welding. Temperature field analysis is the prerequisite for improving the welding quality, welding metallurgy, and mechanical analysis. An accurate grasp of the temperature field distribution on the FSW process plays a vital role. In this research, the temperature field of FSW for 6005 aluminum alloy is simulated and analyzed by SYSWELD software. Then the simulation results were verified by experimental results. First of all, the finite element simulation and theoretical analysis were carried out for the FSW process. Then finite element model was established by using the SYSWELD software. And the temperature field of the FSW process was established by grid partitioning, HSM setting, and subsequent observation. The numerical simulation method is used to analyze the temperature field of the FSW process. Finally, the simulation results are verified and calibrated by the thermocouple temperature test. The influence of different welding parameters (Welding Speed and Rotational Speed) on the temperature field is evaluated by the thermal field curves analysis and some particular nodes analysis of the target area.

This research study investigates the effect of unsaturated polyester toughening on mechanical and... more This research study investigates the effect of unsaturated polyester toughening on mechanical and morphological characteristics of glass fibre reinforced epoxy composites. Here, a polyester/epoxy matrix blend was prepared using an ultrasonicator. Three different epoxy/polyester blended composite specimens (75:25, 50:50 and 25:75) were prepared using the vacuum bag moulding process. The composite samples were evaluated for mechanical properties such as tensile, compression, shear, hardness and impact loadings. The mode-I fracture test is also conducted using a DCB specimen to characterize the inter-laminar fracture behaviour of blended matrix composite specimens. The evaluated results were compared with neat polyester and epoxy composites. The addition of polyester in the epoxy increases the hardness as well as fracture toughness, and it was found to be higher than the neat matrix specimens. But the tensile and compressive response of the blended matrix composites is intermediate between the neat epoxy and polyester composites. The mechanical response of the blended matrix composites degrades when the proportion of the polyester in the blend increases.

Emerald Publishing Limited, 2021

Purpose-This paper aims to illustrate the tolerance optimization method based on the assembly acc... more Purpose-This paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product. Design/methodology/approach-A tolerance optimization method is an excellent way to perform product assembly performance. The tolerance optimization method is adapted to the process analysis of the hatch and skin of an aircraft. In this paper, the tolerance optimization techniques are applied to the tolerance allocation for step difference analysis (example: step difference between aircraft cabin door and fuselage outer skin). First, a mathematical model is described to understand the relationship between manufacturing cost and tolerance cost. Second, the penalty function method is applied to form a new equation for tolerance optimization. Finally, MATLAB software is used to calculate 170 loops iteration to understand the efficiency of the new equation for tolerance optimization. Findings-The tolerance optimization method is based on the assembly accuracy constrain, machinery constrain and the cost of production of the assembly product. The main finding of this paper is the lowest assembly and lowest production costs that met the product tolerance specification. Research limitations/implications-This paper illustrated an efficient method of tolerance allocation for products assembly. After 170 loops iterations, it founds that the results very close to the original required tolerance. But it can easily say that the different number of loops iterations may have a different result. But optimization result must be approximate to the original tolerance requirements. Practical implications-It is evident from Table 4 that the tolerance of the closed loop is 1.3999 after the tolerance distribution is completed, which is less than and very close to the original tolerance of 1.40; the machining precision constraint of the outer skin of the cabin door and the fuselage is satisfied, and the assembly precision constraint of the closed loop is satisfied. Originality/value-The research may support further research studies to minimize cost tolerance allocation using tolerance cost optimization techniques, which must meet the given constrain accuracy for assembly products.