Zahurin Samad - Academia.edu (original) (raw)
Papers by Zahurin Samad
Hole-Making and Drilling Technology for Composites
International Journal of Mechanical and Materials Engineering, 2011
In this paper three-dimensional FEM analysis and experimental flashless cold forging and temperat... more In this paper three-dimensional FEM analysis and experimental flashless cold forging and temperature distribution of aluminum front and back hubs of Autonomous Underwater Vehicle (AUV) propeller is presented. The rigidplastic finite element simulation is performed using DEFORM F-3V6.0, to estimate the optimum load required for the flashless cold forging. The complex profiles of the hubs are modeled using SOLIDWORKS SP4.02007 which is used for the modeling of work-piece and die-punch assembly as well. The work-piece used is of AISI AL6061 and the die material is die steel (AISI D2). The process is optimized to form the propeller back and front hubs. For both the models, three workpieces with different aspect ratios are selected and investigated to obtain the optimum workpiece that gives flashless cold forging with acceptable underfilling. Based on the simulation results, the flash-less cold forging is successfully done on a 100 ton C-type machine. The experimental forged samples are ...
Hole-Making and Drilling Technology for Composites
In this research, three methods for the detection of crack defects on integrated circuit (IC) pac... more In this research, three methods for the detection of crack defects on integrated circuit (IC) packages are proposed. These methods use blob analysis technique in image processing stage, and use multi-layered perceptron (MLP) neural network to classify the IC package. This paper presents the various filters and operations employed in blob analysis. The simulation results have shown, that a two-layer back-propagation neural network, which has a log-sigmoid transfer function in the hidden and output layer, could be trained to classify the IC package image. An early stopping technique was used in this study to provide benefits to the network performance in terms of a decrease in over-fitting. It was found that the optimal number of hidden neurons for the network 1,2 and 3 were 12, 12 and 10. The first method produced an accuracy of 74.82% with 87.72 ms processing time, while the second method utilizing the same classifier, achieved 86.17% accuracy with 119.45 ms processing time. The thi...
This paper proposes an efficient CNC interpolation algorithm for general 2D parametric curves. Th... more This paper proposes an efficient CNC interpolation algorithm for general 2D parametric curves. The proposed interpolator uses reference-pulse or incremental step technique. The algorithm is based upon finding the successive enclosing-lines that the parametric curve intersects. Once the intersected line is identified, the pre-defined closest distance region is used to select the interpolating point without resorting to calculation. Real-time computer simulations indicate that the proposed algorithm increases maximum allowable velocity while still maintaining high precision.
Accuracy of the forging parts becomes critical as the process depends on many factors. Defect may... more Accuracy of the forging parts becomes critical as the process depends on many factors. Defect may harm the assembly and tends to affect the performance of the parts. Therefore, it must be understood and detected as soon as the manufacturing begins. The size and complexity of the part limit the defect to be assessed. This study intent to investigate the defect of the cold embossing pin located at the head of a propeller blade. This is to ensure accurate assembly of the blade. In this work, the effects of design and process parameters on the formation of defect are studied using 2-D finite element analysis. The defect can be measured based on the incomplete filling of the region using the captured images from the FE result. The results seem to show that there is less effect from the diameter of punch and internal cavity, but more obvious due to the distance to the edge. The FE results are in good agreement with the experimental results.
Structural materials, such as composite panels, can only be assembled, and in most cases through ... more Structural materials, such as composite panels, can only be assembled, and in most cases through the use of fasteners, which are fitted into the drilled holes. However, drilling is costly and time consuming, thus affecting productivity. This research aims to develop an alternative method to drilling. In this paper, the precision of the holes was measured and the effects of the die clearance to the areas around the holes were evaluated. Measurement and evaluation were performed based on the profile of the holes constructed using Alicona IFM, a 3D surface measurement technique. Results showed that punching is a potential alternative to drilling but still requires improvements.
IOP Conference Series: Materials Science and Engineering
Welding process is considered as a thermal-mechanical-metallurgical coupled problem. In this stud... more Welding process is considered as a thermal-mechanical-metallurgical coupled problem. In this study, finite element method (FEM) is adopted for predicting the temperature history in Metal Inert Gas (MIG) welding of 5mm thick aluminium 6082 alloy. The Goldak’s double ellipsoidal moving heat source model was used to analyse the influence of peak temperature to the radial distance from the center of the heat source and the thickness of the plate. Temperature-dependent thermal properties of aluminium alloy 6082 in T6 condition and the convective and radiative boundary conditions were included in the model. The finite element code, ANSYS along with APDL command subroutines was employed to obtain the numerical results. The effect of heat input and welding speed on the weld pool shape and temperature distribution were investigated. Finally, the predicted temperature distribution and the size of heat-affected zone were compared with the experimental results. The comparison shows that they ar...
The International Journal of Advanced Manufacturing Technology
Mechanical joints in composite structures are broadly used in many applications due to their acce... more Mechanical joints in composite structures are broadly used in many applications due to their accessibility for disassembly during maintenance. The capability of mechanical joints (bolted joints, pin joints, rivet joints, etc.) depends on the hole quality because the load transmitted via fastener gives rise to stress concentration around the hole-fastener boundary. This experimental study investigates the pattern on the effect of hole preparation techniques, namely, drilling and punching, on carbon-fiber-reinforced polymer with constant geometric parameters to the bearing strength and progressive failure analysis of the hole under tensile loading. A bearing test is conducted according to ASTM D5961 Procedure-A double shear with single-pin fastener using a modified fixture. The progressive failure modes resulting from the experiment are quantified and compared to those in literature. Results reveal clear differences in the bearing-response profiles plotted in the load–displacement graph between the drilling and punching techniques.
SAE International Journal of Materials and Manufacturing
International Journal of the Physical Sciences
Geometrical and dimensional accuracies are two major concerns in precision forging and they becom... more Geometrical and dimensional accuracies are two major concerns in precision forging and they become more critical with increasing part complexity. In this study, the geometrical error of an autonomous underwater vehicle (AUV) propeller blade is quantified by comparing the blade and punch profiles. The nominal geometry of the blade is compared to the blade profile measured using the optical technique Infinite Focus Alicona system to determine profile deviation. The current study aims to investigate the contributions of die shape modifications on the error formation of the two most critical geometries, namely, blade thickness and twist angle. The results show that die modification has a significant effect on geometrical and dimensional errors.
Transactions of Nonferrous Metals Society of China
The present study is aimed to compare the microstructure characteristics and mechanical propertie... more The present study is aimed to compare the microstructure characteristics and mechanical properties of AA6082 in T6 condition of tubular joints fabricated by tungsten inert gas welding (TIG) and metal inert gas welding (MIG) processes. The effect of welding processes was analysed based on optical microscopy image, tensile testing, and Vickers micro-hardness measurements. The results showed that the tensile strengths of the TIG-welded joints were better than those of the MIG-welded joints, due to the contribution of fine equiaxed grains formation with narrower spacing arms. In terms of joint efficiency, the TIG process produced more reliable strength, which was about 25% higher compared to the MIG-joint. A significant decay of hardness was recorded in the adjacent of the weld bead zone, shown in both joints, related to phase transformation, induced by high temperatures experienced by material. A very low hardness, which was about 1.08 GPa, was recorded in the MIG-welded specimens. The extent of the heat-affected-zone (HAZ) in the MIG-welded joints was slightly wider than those of the TIG-welded specimens, which corresponded with a higher heat input per unit length.
Materials Science Forum
Accurate and strong fastener assembly depends on precision of the hole. For structural material l... more Accurate and strong fastener assembly depends on precision of the hole. For structural material likes composites, these criteria is very important. Drilling is the most common method in producing hole on composites. But the main problem of drilling is excessive tool wear that may affect the quality of the holes. Punching is another alternative in making a hole. The main objective of this study is to compare between drilling and punching in terms of hole quality. The scanned images of the produced hole will be captured using commercial 3D optical surface measurement method namely Alicona IFM. The effect to the quality of the produced hole will be measured and compared between drilling and punching.
Structural materials, such as composite panels, must be assembled, and such panels are typically ... more Structural materials, such as composite panels, must be assembled, and such panels are typically constructed via the insertion of a fastener through a drilled hole. The main problem encountered in drilling is delamination, which affects assembly strength. The cost of drilling is also high because of the severe wear on drill bits. The main goal of this research is to develop a new punching method as an alternative to drilling during hole preparation. In this study, the main objective is to investigate the effect of different puncher profiles on the quality of holes punched into carbon fiber reinforcement polymer (CFRP) composite panels. Six types of puncher profiles were fabricated with minimum die clearance (1%), and two quality aspects, namely, incomplete shearing and delamination factor, were measured. The conical puncher incurred the least defects in terms of delamination and yielded an acceptable amount of incomplete shearing in comparison with the other punchers.
Journal of Electrical Engineering and Technology
The purpose of this paper was to find an effective method for measuring electromagnetic torque pr... more The purpose of this paper was to find an effective method for measuring electromagnetic torque produced by a brushless DC motor with single-phase current sensing in real-time. A torque equation is derived from the theory of brushless DC motor. This equation is then validated experimentally with a motor dynamometer. A computer algorithm is also proposed to implement the electromagnetic torque estimation equation in real-time. Electromagnetic torque is a linear function of phase current. Estimating the electromagnetic torque in real-time using single-phase current is not appropriate with existing equations, however, because of the rectangular alternating-pulse nature of the excitation current. With some mathematical manipulation to the existing equations, the equation derived in this paper overcame this limitation. The equation developed is simple and so it is computationally efficient, and it takes only motor torque constant and single-phase current to evaluate the electromagnetic torque; no other parameters such as winding resistances, inductances are needed. The equation derived is limited to the three-phase brushless DC motor. It can, however, easily be extended to the multiphase brushless DC motor with the technique described in this paper.
The International Journal of Advanced Manufacturing Technology
Assembly for a structural material such as a composite panel cannot be avoided. Typically, compos... more Assembly for a structural material such as a composite panel cannot be avoided. Typically, composite panels are assembled using a fastener through a drilled hole. The main problem of drilling is delamination, which affects the strength of the assembly. In addition, the cost of drilling is high because of repeated regrinding of the drill bit. The main goal of this research is to develop a new method as an alternative to drilling hole preparation. In this study, a new simpler method to determine delamination is based on the profile measurement technique. The 2D profile of the punched hole obtained through the focus variation technique is utilized to determine the delamination. A comparison to the developed measurement method shows a good agreement.
MATEC Web of Conferences
Non-uniform thickness section section is considered one of the most effective approaches to reduc... more Non-uniform thickness section section is considered one of the most effective approaches to reduce automotive part weight. Reduction in term of mass and size result in less fuel consumption and greenhouse gases. Thickness is the most significant parameter to formability, therefore forming a section with non-uniform thickness becomes a great challenge. Improper process and incorrect decision may lead to severe defect and one of the main concerns is the springback. This study will focus on springback behaviour of non-uniform thickness AA6061 strip with complex profile using Taguchi Method. Profile projector (PC 3000) is used to measure the spring back and two-line technique is applied to measure angles (after loading) between two lines. Three parameters (i.e. annealing temperature, thickness ratio and bend angle) are studied, and results determine that the most significant parameter is bend angle, followed by thickness ratio, and then by the annealing temperature of the specimen during bending process.
Hole-Making and Drilling Technology for Composites
International Journal of Mechanical and Materials Engineering, 2011
In this paper three-dimensional FEM analysis and experimental flashless cold forging and temperat... more In this paper three-dimensional FEM analysis and experimental flashless cold forging and temperature distribution of aluminum front and back hubs of Autonomous Underwater Vehicle (AUV) propeller is presented. The rigidplastic finite element simulation is performed using DEFORM F-3V6.0, to estimate the optimum load required for the flashless cold forging. The complex profiles of the hubs are modeled using SOLIDWORKS SP4.02007 which is used for the modeling of work-piece and die-punch assembly as well. The work-piece used is of AISI AL6061 and the die material is die steel (AISI D2). The process is optimized to form the propeller back and front hubs. For both the models, three workpieces with different aspect ratios are selected and investigated to obtain the optimum workpiece that gives flashless cold forging with acceptable underfilling. Based on the simulation results, the flash-less cold forging is successfully done on a 100 ton C-type machine. The experimental forged samples are ...
Hole-Making and Drilling Technology for Composites
In this research, three methods for the detection of crack defects on integrated circuit (IC) pac... more In this research, three methods for the detection of crack defects on integrated circuit (IC) packages are proposed. These methods use blob analysis technique in image processing stage, and use multi-layered perceptron (MLP) neural network to classify the IC package. This paper presents the various filters and operations employed in blob analysis. The simulation results have shown, that a two-layer back-propagation neural network, which has a log-sigmoid transfer function in the hidden and output layer, could be trained to classify the IC package image. An early stopping technique was used in this study to provide benefits to the network performance in terms of a decrease in over-fitting. It was found that the optimal number of hidden neurons for the network 1,2 and 3 were 12, 12 and 10. The first method produced an accuracy of 74.82% with 87.72 ms processing time, while the second method utilizing the same classifier, achieved 86.17% accuracy with 119.45 ms processing time. The thi...
This paper proposes an efficient CNC interpolation algorithm for general 2D parametric curves. Th... more This paper proposes an efficient CNC interpolation algorithm for general 2D parametric curves. The proposed interpolator uses reference-pulse or incremental step technique. The algorithm is based upon finding the successive enclosing-lines that the parametric curve intersects. Once the intersected line is identified, the pre-defined closest distance region is used to select the interpolating point without resorting to calculation. Real-time computer simulations indicate that the proposed algorithm increases maximum allowable velocity while still maintaining high precision.
Accuracy of the forging parts becomes critical as the process depends on many factors. Defect may... more Accuracy of the forging parts becomes critical as the process depends on many factors. Defect may harm the assembly and tends to affect the performance of the parts. Therefore, it must be understood and detected as soon as the manufacturing begins. The size and complexity of the part limit the defect to be assessed. This study intent to investigate the defect of the cold embossing pin located at the head of a propeller blade. This is to ensure accurate assembly of the blade. In this work, the effects of design and process parameters on the formation of defect are studied using 2-D finite element analysis. The defect can be measured based on the incomplete filling of the region using the captured images from the FE result. The results seem to show that there is less effect from the diameter of punch and internal cavity, but more obvious due to the distance to the edge. The FE results are in good agreement with the experimental results.
Structural materials, such as composite panels, can only be assembled, and in most cases through ... more Structural materials, such as composite panels, can only be assembled, and in most cases through the use of fasteners, which are fitted into the drilled holes. However, drilling is costly and time consuming, thus affecting productivity. This research aims to develop an alternative method to drilling. In this paper, the precision of the holes was measured and the effects of the die clearance to the areas around the holes were evaluated. Measurement and evaluation were performed based on the profile of the holes constructed using Alicona IFM, a 3D surface measurement technique. Results showed that punching is a potential alternative to drilling but still requires improvements.
IOP Conference Series: Materials Science and Engineering
Welding process is considered as a thermal-mechanical-metallurgical coupled problem. In this stud... more Welding process is considered as a thermal-mechanical-metallurgical coupled problem. In this study, finite element method (FEM) is adopted for predicting the temperature history in Metal Inert Gas (MIG) welding of 5mm thick aluminium 6082 alloy. The Goldak’s double ellipsoidal moving heat source model was used to analyse the influence of peak temperature to the radial distance from the center of the heat source and the thickness of the plate. Temperature-dependent thermal properties of aluminium alloy 6082 in T6 condition and the convective and radiative boundary conditions were included in the model. The finite element code, ANSYS along with APDL command subroutines was employed to obtain the numerical results. The effect of heat input and welding speed on the weld pool shape and temperature distribution were investigated. Finally, the predicted temperature distribution and the size of heat-affected zone were compared with the experimental results. The comparison shows that they ar...
The International Journal of Advanced Manufacturing Technology
Mechanical joints in composite structures are broadly used in many applications due to their acce... more Mechanical joints in composite structures are broadly used in many applications due to their accessibility for disassembly during maintenance. The capability of mechanical joints (bolted joints, pin joints, rivet joints, etc.) depends on the hole quality because the load transmitted via fastener gives rise to stress concentration around the hole-fastener boundary. This experimental study investigates the pattern on the effect of hole preparation techniques, namely, drilling and punching, on carbon-fiber-reinforced polymer with constant geometric parameters to the bearing strength and progressive failure analysis of the hole under tensile loading. A bearing test is conducted according to ASTM D5961 Procedure-A double shear with single-pin fastener using a modified fixture. The progressive failure modes resulting from the experiment are quantified and compared to those in literature. Results reveal clear differences in the bearing-response profiles plotted in the load–displacement graph between the drilling and punching techniques.
SAE International Journal of Materials and Manufacturing
International Journal of the Physical Sciences
Geometrical and dimensional accuracies are two major concerns in precision forging and they becom... more Geometrical and dimensional accuracies are two major concerns in precision forging and they become more critical with increasing part complexity. In this study, the geometrical error of an autonomous underwater vehicle (AUV) propeller blade is quantified by comparing the blade and punch profiles. The nominal geometry of the blade is compared to the blade profile measured using the optical technique Infinite Focus Alicona system to determine profile deviation. The current study aims to investigate the contributions of die shape modifications on the error formation of the two most critical geometries, namely, blade thickness and twist angle. The results show that die modification has a significant effect on geometrical and dimensional errors.
Transactions of Nonferrous Metals Society of China
The present study is aimed to compare the microstructure characteristics and mechanical propertie... more The present study is aimed to compare the microstructure characteristics and mechanical properties of AA6082 in T6 condition of tubular joints fabricated by tungsten inert gas welding (TIG) and metal inert gas welding (MIG) processes. The effect of welding processes was analysed based on optical microscopy image, tensile testing, and Vickers micro-hardness measurements. The results showed that the tensile strengths of the TIG-welded joints were better than those of the MIG-welded joints, due to the contribution of fine equiaxed grains formation with narrower spacing arms. In terms of joint efficiency, the TIG process produced more reliable strength, which was about 25% higher compared to the MIG-joint. A significant decay of hardness was recorded in the adjacent of the weld bead zone, shown in both joints, related to phase transformation, induced by high temperatures experienced by material. A very low hardness, which was about 1.08 GPa, was recorded in the MIG-welded specimens. The extent of the heat-affected-zone (HAZ) in the MIG-welded joints was slightly wider than those of the TIG-welded specimens, which corresponded with a higher heat input per unit length.
Materials Science Forum
Accurate and strong fastener assembly depends on precision of the hole. For structural material l... more Accurate and strong fastener assembly depends on precision of the hole. For structural material likes composites, these criteria is very important. Drilling is the most common method in producing hole on composites. But the main problem of drilling is excessive tool wear that may affect the quality of the holes. Punching is another alternative in making a hole. The main objective of this study is to compare between drilling and punching in terms of hole quality. The scanned images of the produced hole will be captured using commercial 3D optical surface measurement method namely Alicona IFM. The effect to the quality of the produced hole will be measured and compared between drilling and punching.
Structural materials, such as composite panels, must be assembled, and such panels are typically ... more Structural materials, such as composite panels, must be assembled, and such panels are typically constructed via the insertion of a fastener through a drilled hole. The main problem encountered in drilling is delamination, which affects assembly strength. The cost of drilling is also high because of the severe wear on drill bits. The main goal of this research is to develop a new punching method as an alternative to drilling during hole preparation. In this study, the main objective is to investigate the effect of different puncher profiles on the quality of holes punched into carbon fiber reinforcement polymer (CFRP) composite panels. Six types of puncher profiles were fabricated with minimum die clearance (1%), and two quality aspects, namely, incomplete shearing and delamination factor, were measured. The conical puncher incurred the least defects in terms of delamination and yielded an acceptable amount of incomplete shearing in comparison with the other punchers.
Journal of Electrical Engineering and Technology
The purpose of this paper was to find an effective method for measuring electromagnetic torque pr... more The purpose of this paper was to find an effective method for measuring electromagnetic torque produced by a brushless DC motor with single-phase current sensing in real-time. A torque equation is derived from the theory of brushless DC motor. This equation is then validated experimentally with a motor dynamometer. A computer algorithm is also proposed to implement the electromagnetic torque estimation equation in real-time. Electromagnetic torque is a linear function of phase current. Estimating the electromagnetic torque in real-time using single-phase current is not appropriate with existing equations, however, because of the rectangular alternating-pulse nature of the excitation current. With some mathematical manipulation to the existing equations, the equation derived in this paper overcame this limitation. The equation developed is simple and so it is computationally efficient, and it takes only motor torque constant and single-phase current to evaluate the electromagnetic torque; no other parameters such as winding resistances, inductances are needed. The equation derived is limited to the three-phase brushless DC motor. It can, however, easily be extended to the multiphase brushless DC motor with the technique described in this paper.
The International Journal of Advanced Manufacturing Technology
Assembly for a structural material such as a composite panel cannot be avoided. Typically, compos... more Assembly for a structural material such as a composite panel cannot be avoided. Typically, composite panels are assembled using a fastener through a drilled hole. The main problem of drilling is delamination, which affects the strength of the assembly. In addition, the cost of drilling is high because of repeated regrinding of the drill bit. The main goal of this research is to develop a new method as an alternative to drilling hole preparation. In this study, a new simpler method to determine delamination is based on the profile measurement technique. The 2D profile of the punched hole obtained through the focus variation technique is utilized to determine the delamination. A comparison to the developed measurement method shows a good agreement.
MATEC Web of Conferences
Non-uniform thickness section section is considered one of the most effective approaches to reduc... more Non-uniform thickness section section is considered one of the most effective approaches to reduce automotive part weight. Reduction in term of mass and size result in less fuel consumption and greenhouse gases. Thickness is the most significant parameter to formability, therefore forming a section with non-uniform thickness becomes a great challenge. Improper process and incorrect decision may lead to severe defect and one of the main concerns is the springback. This study will focus on springback behaviour of non-uniform thickness AA6061 strip with complex profile using Taguchi Method. Profile projector (PC 3000) is used to measure the spring back and two-line technique is applied to measure angles (after loading) between two lines. Three parameters (i.e. annealing temperature, thickness ratio and bend angle) are studied, and results determine that the most significant parameter is bend angle, followed by thickness ratio, and then by the annealing temperature of the specimen during bending process.