Amro Youssef | Obong University (original) (raw)

Papers by Amro Youssef

The International Conference on Applied Mechanics and Mechanical Engineering (Print), May 1, 2010

Automated feature recognition has recognized as the front end of fully automated computer aided p... more Automated feature recognition has recognized as the front end of fully automated computer aided process planning (CAPP) systems. Automated feature recognition is considered to be the link between computer aided design (CAD) and CAPP systems. Feature recognition converts the geometrical and topological data contained in CAD file into application orientated features for planning purposes. This work introduces an automated rule based feature recognition algorithm to extract prismatic features from a boundary representation (Brep) solid model. The automatic feature recognition algorithm is developed using ACIS geometric kernel and C++ object oriented programming. The recognition system input is a Brep solid model in sat format. The developed algorithm is a part of a complete computer aided inspection planning system.

The International Conference on Chemical and Environmental Engineering (Print), May 1, 2008

Polymer blends represent a field of intensive research. In the present work, different rubber ble... more Polymer blends represent a field of intensive research. In the present work, different rubber blends based on nitrile butadiene rubber, NBR (N3980-39% acrylonitrile) have been selected to get a product with high oil resistance and good mechanical properties. The ratio of each component (NBR and chloroprene rubber CR) in NBR-CR blends has been varied and the corresponding vulcanizing systems have been carefully selected. The rheological properties of the different blends obtained were evaluated. For instance, the scorch time, optimum time of vulcanization have been determined and correlated with the blends composition. The mechanical properties, swelling in toluene and different oils have been evaluated using standard techniques. Besides, the effects of different vulcanizing systems on the mechanical properties and degree of swelling of the vulcanized blends in toluene, as well as the resistance of the blends to the oils has been evaluated. It has been found that the type of rubber and the composition of blends clearly affect their resistance to oils. In contrast, the type of crosslinking and crosslinking density slightly affect the oil resistance of the corresponding vulcanizates.

Coordinate measuring machines (CMMs) have been recognized as a powerful tool for inspection and m... more Coordinate measuring machines (CMMs) have been recognized as a powerful tool for inspection and measurement purposes. Maximum utilization of CMMs requires the development of an automated inspection planning system. A computer-aided inspection planning (CAIP) system leads to minimization of the total time needed for inspection process and hence the overall cost of the final product. This work introduces a computer aided inspection system that reads a B-rep solid model in SAT format as an input and produces the final CMM program in DMIS format. The system includes the following: rule-based feature recognition module that identifies and extracts the necessary inspection features from the solid model, sampling strategy module to determine the number and the location of the needed measuring points on each inspection feature, accessibility analysis module to determine the number of probe orientations that can reach the measured points without collision, finally, a clustering module to minimize the total number of probe orientations need to fully inspect the entire part. All algorithms are developed using ACIS geometric kernel and object oriented programming using C++. The results are verified on CMM.

Journal of Engineering and Science Research

Friction and wear are two major factors affecting the disk brake service life. Carbon-carbon comp... more Friction and wear are two major factors affecting the disk brake service life. Carbon-carbon composite materials have good stable friction properties, which enable them to operate as friction material in aircraft brakes application. This article discusses a wear simulation method for predicting the wear amount of c/c composite aircraft brakes under simulated operating conditions. A modified version of Archard’s wear equation is used in 2-D axisymmetric finite element model in order to predict the disk brake friction surfaces wear progression. The finite element commercial software COMSOL Multiphysics 5.5 is used to simulate wear and is presented in this paper. Wear law was implemented as a boundary ordinary differential equation (ODE) in a COMSOL Multiphysics simulation, considering wear depth (thickness) as the independent variable. Frictional heat generation is simulated as heat affects on material thermal properties and as a result surface deformation. Element removal technique i...

The International Conference on Applied Mechanics and Mechanical Engineering, 2018

In metal cutting, the prediction of cutting forces has been the focus of research for very long t... more In metal cutting, the prediction of cutting forces has been the focus of research for very long time. The reason for that is to decrease the cost of performing experimental work whenever the cutting of new material is needed. In recent years a new application for metal cutting was introduced due to the miniaturization of components and the invention of micro electro-mechanical system MEMS. This has led to the introduction of micro machining. Thus the analysis of the cutting system needed revisions. This is because of the domination of other factors during cutting process. Among these factors are the minimum chip thickness and the ploughing forces. In this work the modeling of orthogonal, oblique and milling cutting process in micro scale is presented. The results are verified using published experimental results.

The International Conference on Applied Mechanics and Mechanical Engineering (Print), May 1, 2014

Injection molding is defined as a cyclic process for producing identical products from a mold and... more Injection molding is defined as a cyclic process for producing identical products from a mold and it is the most widely used polymer processing operation. The main advantage of this process is the capacity of repetitively fabricating parts. Certain challenges face this process in order to get a defect free product. The control of the cavity pressure is important for maintaining the quality of the plastic product. The common practice in industry is to have a fixed value for the pressure during the filling phase and also during the packing phase of the process. This may lead to the introduction of defects in the final product. This paper presents a mathematical model and experimental verification of a strategy to control the cavity pressure profile during the filling and the packing phases to minimize the flow marks, warpage and shrinkage for an ABS injection molded product. For the packing phase, the efficient frontier method is used to obtain the optimum pressure for minimizing the combination effect between the warpage and the shrinkage. This may be used as a tool for weighing the behavior of these two defects with the variation of the packing pressure. The results showed the effectiveness of the mathematical model used for predicting the filling and pressures to minimize the investigated defects.

Modeling and Numerical Simulation of Material Science, 2013

This research work is focused on simulation of laser assisted turning as a new solution for machi... more This research work is focused on simulation of laser assisted turning as a new solution for machining of hard steels. A transient, three-dimensional model was developed to predict the temperature distribution of a rotated cylindrical steel workpiece subjected to a localized heating using a moving Gaussian laser beam. In this regard, a User-Defined Function was created to overcome the problem of a moving Gaussian heat source' definition. This User-Defined Function was compiled into a finite volume software package (Fluent ®), where three-dimensional single precision solver was used for analysis. Based on this model, simulation of the surface temperature of 32 mm diameter workpiece of AISI51 50H steel was performed as a function of time at a specific distance behind the laser beam spot, which is corresponding to 30˚ angle from the laser beam. The simulation results were compared with other published data of the same steel type where a close agreement was obtained. The verified model was used for simulation of laser assisted turning of 20 mm diameter workpiece of AISI D2 tool steel. The cutting depth, behind the laser beam, was set at a distance corresponding to 60˚ angle from the laser beam for having sufficient access for handling both laser head and cutting tool. This cutting depth was studied as a function of different lasers and machining parameters. The results indicated that the optimum parameters for successful laser-assisted turning process of the concerned steels are 800 W laser power, 5 mm laser beam spot diameter, 20 sec preheating time, 0.8 mm/sec laser scanning speed, 300 rpm rotational speed and 0.8 mm/sec feed rate. These parameters ensure easy/successful cutting of 1 mm depth in one pass without deteriorating the properties of the remaining bulk material. It can be deduced that the developed model might provide a useful tool for online process control of different steel types regardless of their physical properties and geometries.

Journal of Manufacturing Processes

Machining Science and Technology

Journal of Engineering Science and Military Technologies

Hard steels are extensively used in gamut of uses such as aerospace, vehicles and die and mold in... more Hard steels are extensively used in gamut of uses such as aerospace, vehicles and die and mold industries. These materials have high strength and hardness which leads to a difficulty in their manufacturing. In addition to the required high forces during the production by machining and the resulting tool wear, it needs machine tools with high stiffness. Such characteristics will result in a production cost that can reach half of the product cost and high investments in addition to the need for subsequent finishing operations. Laser assisted machining (LAM) represents a new step towards a promising technique for machining new materials that are difficult to machine. It offers local heating of the work before conventional cutting takes place. Tool steel is an important example of these materials. In this work laser assisted turning of tool steel DIN 1.2379 is investigated. Nd:YAG pulsed laser head of 350 W power is used to assist conventional turning operation. For process evaluation, a comparison of conventional and LAM was introduced considering tool life, cutting forces. The influences of different cutting speeds, depth of cuts and laser powers were discussed. The experimental results showed a considerable increase of tool life, a reduction in cutting forces, when using LAM in turning operation.

Journal of Engineering Science and Military Technologies

Block ciphers cryptanalysis is serious challenge specially with the existing of the powerful bloc... more Block ciphers cryptanalysis is serious challenge specially with the existing of the powerful block ciphers that require massive number of plaintext-ciphertext pairs to perform a successful attack. Algebraic attack is superior among different attack types as it does require the smallest number of such pairs. On the other hand, the equations describe the input/output relations should be in hand to execute the algebraic attack. In this paper, we present the method of collecting the input/ output algebraic equations for 2-key simplified 3-DES as a miniature example of the 2-key 3-DES. The simplified DES has similar structure and characteristics to DES with the privilege of using smaller parameters than DES. Also, we prove that the complementation property of DES can be used to double the number of obtained algebraic equations for 3-DES variants and consequently decreasing the required number of plaintext-ciphertext pairs. Finally, we compared the expected number of obtained equations and variables in both 2-key simplified 3-DES and 2-key 3-DES.

The International Conference on Applied Mechanics and Mechanical Engineering

Design of laser cavities is a complicated process. It includes several optical, geometrical and m... more Design of laser cavities is a complicated process. It includes several optical, geometrical and material parameters. Computer Aided Design of laser cavities reduces the time and effort required to reach the optimum design. In this paper an accurate and fast three dimensional CAD model for simulating solid-state laser systems is developed. Numerical estimations of the geometrical transfer efficiency of various cavities are presented. Analytical and iterative methods to achieve a feasible converged solution for designing optimum pumping champers which contains different geometrical dimensions of laser rods, flash lamps and walls reflectivity are discussed. A simulation study of the pumping efficiency of the laser heads with respect to the cavity geometry, different geometries of laser rods and flashlamps, and reflecting coatings have been carried out. The goal is to achieve a maximum concentration of the light flux of the pumping source towards the active medium. Results are presented using Matlab and Microsoft office excel. Computer aided design is then used to create three dimensional parametric model of laser cavity assembly. The proposed model has been compared with published results and shown to be very accurate and efficient for modeling three-dimensional solid-state laser chambers.

The International Conference on Applied Mechanics and Mechanical Engineering

Automated feature recognition has recognized as the front end of fully automated computer aided p... more Automated feature recognition has recognized as the front end of fully automated computer aided process planning (CAPP) systems. Automated feature recognition is considered to be the link between computer aided design (CAD) and CAPP systems. Feature recognition converts the geometrical and topological data contained in CAD file into application orientated features for planning purposes. This work introduces an automated rule based feature recognition algorithm to extract prismatic features from a boundary representation (Brep) solid model. The automatic feature recognition algorithm is developed using ACIS geometric kernel and C++ object oriented programming. The recognition system input is a Brep solid model in sat format. The developed algorithm is a part of a complete computer aided inspection planning system.

CIRP Journal of Manufacturing Science and Technology

... xiii Page 16. 10.4.3 Multi-Tool Selection ..... 10.4.4 Flank Milling of Non-developable Surfa... more ... xiii Page 16. 10.4.3 Multi-Tool Selection ..... 10.4.4 Flank Milling of Non-developable Surfaces 10.4.5 Integration of Five Axis Machining Process Evaluation BIBLIOGRAPHY . . . . ... checking strategy is presented. The flank milling of the developable surface is also investigated. ...

Advanced Materials Research, 2012

Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft ind... more Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft industries. Concerning the assembly, welding was extensively applied in the car industry. Nevertheless, welding defects generated during the process result in reduction in strength of both the weld; and heat affected zone which could limit its applications. Electron beam welding (EBW) has unique advantages over other traditional fusion welding methods due to its high-energy density, deep penetration, large depth-to-width ratio and the resulting very small heat affected zone. Optimization of EB welded joint of 2219 Al-alloy, from the yield strength, hardness and bead geometry point of view, is the topic of this study. Taguchi methodology with grey relation analysis has been applied to find the optimal welding parameters for welding of a sheet of the mentioned aluminum alloy with electron beam. The optimal welding parameters have been selected and verified experimentally.

2012 International Conference on Engineering and Technology (ICET), 2012

Advanced Materials Research, Nov 1, 2012

Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft ind... more Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft industries. Concerning the assembly, welding was extensively applied in the car industry. Nevertheless, welding defects generated during the process result in reduction in strength of both the weld; and heat affected zone which could limit its applications. Electron beam welding (EBW) has unique advantages over other traditional fusion welding methods due to its high-energy density, deep penetration, large depth-to-width ratio and the resulting very small heat affected zone. Optimization of EB welded joint of 2219 Al-alloy, from the yield strength, hardness and bead geometry point of view, is the topic of this study. Taguchi methodology with grey relation analysis has been applied to find the optimal welding parameters for welding of a sheet of the mentioned aluminum alloy with electron beam. The optimal welding parameters have been selected and verified experimentally.

Modeling and Numerical Simulation of Material Science, 2013

This research work is focused on simulation of laser assisted turning as a new solution for machi... more This research work is focused on simulation of laser assisted turning as a new solution for machining of hard steels. A transient, three-dimensional model was developed to predict the temperature distribution of a rotated cylindrical steel workpiece subjected to a localized heating using a moving Gaussian laser beam. In this regard, a User-Defined Function was created to overcome the problem of a moving Gaussian heat source' definition. This User-Defined Function was compiled into a finite volume software package (Fluent ® ), where three-dimensional single precision solver was used for analysis. Based on this model, simulation of the surface temperature of 32 mm diameter workpiece of AISI51 50H steel was performed as a function of time at a specific distance behind the laser beam spot, which is corresponding to 30˚ angle from the laser beam. The simulation results were compared with other published data of the same steel type where a close agreement was obtained. The verified model was used for simulation of laser assisted turning of 20 mm diameter workpiece of AISI D2 tool steel. The cutting depth, behind the laser beam, was set at a distance corresponding to 60˚ angle from the laser beam for having sufficient access for handling both laser head and cutting tool. This cutting depth was studied as a function of different lasers and machining parameters. The results indicated that the optimum parameters for successful laser-assisted turning process of the concerned steels are 800 W laser power, 5 mm laser beam spot diameter, 20 sec preheating time, 0.8 mm/sec laser scanning speed, 300 rpm rotational speed and 0.8 mm/sec feed rate. These parameters ensure easy/successful cutting of 1 mm depth in one pass without deteriorating the properties of the remaining bulk material. It can be deduced that the developed model might provide a useful tool for online process control of different steel types regardless of their physical properties and geometries.

The International Conference on Applied Mechanics and Mechanical Engineering (Print), May 1, 2010

Automated feature recognition has recognized as the front end of fully automated computer aided p... more Automated feature recognition has recognized as the front end of fully automated computer aided process planning (CAPP) systems. Automated feature recognition is considered to be the link between computer aided design (CAD) and CAPP systems. Feature recognition converts the geometrical and topological data contained in CAD file into application orientated features for planning purposes. This work introduces an automated rule based feature recognition algorithm to extract prismatic features from a boundary representation (Brep) solid model. The automatic feature recognition algorithm is developed using ACIS geometric kernel and C++ object oriented programming. The recognition system input is a Brep solid model in sat format. The developed algorithm is a part of a complete computer aided inspection planning system.

The International Conference on Chemical and Environmental Engineering (Print), May 1, 2008

Polymer blends represent a field of intensive research. In the present work, different rubber ble... more Polymer blends represent a field of intensive research. In the present work, different rubber blends based on nitrile butadiene rubber, NBR (N3980-39% acrylonitrile) have been selected to get a product with high oil resistance and good mechanical properties. The ratio of each component (NBR and chloroprene rubber CR) in NBR-CR blends has been varied and the corresponding vulcanizing systems have been carefully selected. The rheological properties of the different blends obtained were evaluated. For instance, the scorch time, optimum time of vulcanization have been determined and correlated with the blends composition. The mechanical properties, swelling in toluene and different oils have been evaluated using standard techniques. Besides, the effects of different vulcanizing systems on the mechanical properties and degree of swelling of the vulcanized blends in toluene, as well as the resistance of the blends to the oils has been evaluated. It has been found that the type of rubber and the composition of blends clearly affect their resistance to oils. In contrast, the type of crosslinking and crosslinking density slightly affect the oil resistance of the corresponding vulcanizates.

Coordinate measuring machines (CMMs) have been recognized as a powerful tool for inspection and m... more Coordinate measuring machines (CMMs) have been recognized as a powerful tool for inspection and measurement purposes. Maximum utilization of CMMs requires the development of an automated inspection planning system. A computer-aided inspection planning (CAIP) system leads to minimization of the total time needed for inspection process and hence the overall cost of the final product. This work introduces a computer aided inspection system that reads a B-rep solid model in SAT format as an input and produces the final CMM program in DMIS format. The system includes the following: rule-based feature recognition module that identifies and extracts the necessary inspection features from the solid model, sampling strategy module to determine the number and the location of the needed measuring points on each inspection feature, accessibility analysis module to determine the number of probe orientations that can reach the measured points without collision, finally, a clustering module to minimize the total number of probe orientations need to fully inspect the entire part. All algorithms are developed using ACIS geometric kernel and object oriented programming using C++. The results are verified on CMM.

Journal of Engineering and Science Research

Friction and wear are two major factors affecting the disk brake service life. Carbon-carbon comp... more Friction and wear are two major factors affecting the disk brake service life. Carbon-carbon composite materials have good stable friction properties, which enable them to operate as friction material in aircraft brakes application. This article discusses a wear simulation method for predicting the wear amount of c/c composite aircraft brakes under simulated operating conditions. A modified version of Archard’s wear equation is used in 2-D axisymmetric finite element model in order to predict the disk brake friction surfaces wear progression. The finite element commercial software COMSOL Multiphysics 5.5 is used to simulate wear and is presented in this paper. Wear law was implemented as a boundary ordinary differential equation (ODE) in a COMSOL Multiphysics simulation, considering wear depth (thickness) as the independent variable. Frictional heat generation is simulated as heat affects on material thermal properties and as a result surface deformation. Element removal technique i...

The International Conference on Applied Mechanics and Mechanical Engineering, 2018

In metal cutting, the prediction of cutting forces has been the focus of research for very long t... more In metal cutting, the prediction of cutting forces has been the focus of research for very long time. The reason for that is to decrease the cost of performing experimental work whenever the cutting of new material is needed. In recent years a new application for metal cutting was introduced due to the miniaturization of components and the invention of micro electro-mechanical system MEMS. This has led to the introduction of micro machining. Thus the analysis of the cutting system needed revisions. This is because of the domination of other factors during cutting process. Among these factors are the minimum chip thickness and the ploughing forces. In this work the modeling of orthogonal, oblique and milling cutting process in micro scale is presented. The results are verified using published experimental results.

The International Conference on Applied Mechanics and Mechanical Engineering (Print), May 1, 2014

Injection molding is defined as a cyclic process for producing identical products from a mold and... more Injection molding is defined as a cyclic process for producing identical products from a mold and it is the most widely used polymer processing operation. The main advantage of this process is the capacity of repetitively fabricating parts. Certain challenges face this process in order to get a defect free product. The control of the cavity pressure is important for maintaining the quality of the plastic product. The common practice in industry is to have a fixed value for the pressure during the filling phase and also during the packing phase of the process. This may lead to the introduction of defects in the final product. This paper presents a mathematical model and experimental verification of a strategy to control the cavity pressure profile during the filling and the packing phases to minimize the flow marks, warpage and shrinkage for an ABS injection molded product. For the packing phase, the efficient frontier method is used to obtain the optimum pressure for minimizing the combination effect between the warpage and the shrinkage. This may be used as a tool for weighing the behavior of these two defects with the variation of the packing pressure. The results showed the effectiveness of the mathematical model used for predicting the filling and pressures to minimize the investigated defects.

Modeling and Numerical Simulation of Material Science, 2013

This research work is focused on simulation of laser assisted turning as a new solution for machi... more This research work is focused on simulation of laser assisted turning as a new solution for machining of hard steels. A transient, three-dimensional model was developed to predict the temperature distribution of a rotated cylindrical steel workpiece subjected to a localized heating using a moving Gaussian laser beam. In this regard, a User-Defined Function was created to overcome the problem of a moving Gaussian heat source' definition. This User-Defined Function was compiled into a finite volume software package (Fluent ®), where three-dimensional single precision solver was used for analysis. Based on this model, simulation of the surface temperature of 32 mm diameter workpiece of AISI51 50H steel was performed as a function of time at a specific distance behind the laser beam spot, which is corresponding to 30˚ angle from the laser beam. The simulation results were compared with other published data of the same steel type where a close agreement was obtained. The verified model was used for simulation of laser assisted turning of 20 mm diameter workpiece of AISI D2 tool steel. The cutting depth, behind the laser beam, was set at a distance corresponding to 60˚ angle from the laser beam for having sufficient access for handling both laser head and cutting tool. This cutting depth was studied as a function of different lasers and machining parameters. The results indicated that the optimum parameters for successful laser-assisted turning process of the concerned steels are 800 W laser power, 5 mm laser beam spot diameter, 20 sec preheating time, 0.8 mm/sec laser scanning speed, 300 rpm rotational speed and 0.8 mm/sec feed rate. These parameters ensure easy/successful cutting of 1 mm depth in one pass without deteriorating the properties of the remaining bulk material. It can be deduced that the developed model might provide a useful tool for online process control of different steel types regardless of their physical properties and geometries.

Journal of Manufacturing Processes

Machining Science and Technology

Journal of Engineering Science and Military Technologies

Hard steels are extensively used in gamut of uses such as aerospace, vehicles and die and mold in... more Hard steels are extensively used in gamut of uses such as aerospace, vehicles and die and mold industries. These materials have high strength and hardness which leads to a difficulty in their manufacturing. In addition to the required high forces during the production by machining and the resulting tool wear, it needs machine tools with high stiffness. Such characteristics will result in a production cost that can reach half of the product cost and high investments in addition to the need for subsequent finishing operations. Laser assisted machining (LAM) represents a new step towards a promising technique for machining new materials that are difficult to machine. It offers local heating of the work before conventional cutting takes place. Tool steel is an important example of these materials. In this work laser assisted turning of tool steel DIN 1.2379 is investigated. Nd:YAG pulsed laser head of 350 W power is used to assist conventional turning operation. For process evaluation, a comparison of conventional and LAM was introduced considering tool life, cutting forces. The influences of different cutting speeds, depth of cuts and laser powers were discussed. The experimental results showed a considerable increase of tool life, a reduction in cutting forces, when using LAM in turning operation.

Journal of Engineering Science and Military Technologies

Block ciphers cryptanalysis is serious challenge specially with the existing of the powerful bloc... more Block ciphers cryptanalysis is serious challenge specially with the existing of the powerful block ciphers that require massive number of plaintext-ciphertext pairs to perform a successful attack. Algebraic attack is superior among different attack types as it does require the smallest number of such pairs. On the other hand, the equations describe the input/output relations should be in hand to execute the algebraic attack. In this paper, we present the method of collecting the input/ output algebraic equations for 2-key simplified 3-DES as a miniature example of the 2-key 3-DES. The simplified DES has similar structure and characteristics to DES with the privilege of using smaller parameters than DES. Also, we prove that the complementation property of DES can be used to double the number of obtained algebraic equations for 3-DES variants and consequently decreasing the required number of plaintext-ciphertext pairs. Finally, we compared the expected number of obtained equations and variables in both 2-key simplified 3-DES and 2-key 3-DES.

The International Conference on Applied Mechanics and Mechanical Engineering

Design of laser cavities is a complicated process. It includes several optical, geometrical and m... more Design of laser cavities is a complicated process. It includes several optical, geometrical and material parameters. Computer Aided Design of laser cavities reduces the time and effort required to reach the optimum design. In this paper an accurate and fast three dimensional CAD model for simulating solid-state laser systems is developed. Numerical estimations of the geometrical transfer efficiency of various cavities are presented. Analytical and iterative methods to achieve a feasible converged solution for designing optimum pumping champers which contains different geometrical dimensions of laser rods, flash lamps and walls reflectivity are discussed. A simulation study of the pumping efficiency of the laser heads with respect to the cavity geometry, different geometries of laser rods and flashlamps, and reflecting coatings have been carried out. The goal is to achieve a maximum concentration of the light flux of the pumping source towards the active medium. Results are presented using Matlab and Microsoft office excel. Computer aided design is then used to create three dimensional parametric model of laser cavity assembly. The proposed model has been compared with published results and shown to be very accurate and efficient for modeling three-dimensional solid-state laser chambers.

The International Conference on Applied Mechanics and Mechanical Engineering

Automated feature recognition has recognized as the front end of fully automated computer aided p... more Automated feature recognition has recognized as the front end of fully automated computer aided process planning (CAPP) systems. Automated feature recognition is considered to be the link between computer aided design (CAD) and CAPP systems. Feature recognition converts the geometrical and topological data contained in CAD file into application orientated features for planning purposes. This work introduces an automated rule based feature recognition algorithm to extract prismatic features from a boundary representation (Brep) solid model. The automatic feature recognition algorithm is developed using ACIS geometric kernel and C++ object oriented programming. The recognition system input is a Brep solid model in sat format. The developed algorithm is a part of a complete computer aided inspection planning system.

CIRP Journal of Manufacturing Science and Technology

... xiii Page 16. 10.4.3 Multi-Tool Selection ..... 10.4.4 Flank Milling of Non-developable Surfa... more ... xiii Page 16. 10.4.3 Multi-Tool Selection ..... 10.4.4 Flank Milling of Non-developable Surfaces 10.4.5 Integration of Five Axis Machining Process Evaluation BIBLIOGRAPHY . . . . ... checking strategy is presented. The flank milling of the developable surface is also investigated. ...

Advanced Materials Research, 2012

Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft ind... more Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft industries. Concerning the assembly, welding was extensively applied in the car industry. Nevertheless, welding defects generated during the process result in reduction in strength of both the weld; and heat affected zone which could limit its applications. Electron beam welding (EBW) has unique advantages over other traditional fusion welding methods due to its high-energy density, deep penetration, large depth-to-width ratio and the resulting very small heat affected zone. Optimization of EB welded joint of 2219 Al-alloy, from the yield strength, hardness and bead geometry point of view, is the topic of this study. Taguchi methodology with grey relation analysis has been applied to find the optimal welding parameters for welding of a sheet of the mentioned aluminum alloy with electron beam. The optimal welding parameters have been selected and verified experimentally.

2012 International Conference on Engineering and Technology (ICET), 2012

Advanced Materials Research, Nov 1, 2012

Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft ind... more Aluminum alloys are the subject of increasing interest in the automotive, as well as aircraft industries. Concerning the assembly, welding was extensively applied in the car industry. Nevertheless, welding defects generated during the process result in reduction in strength of both the weld; and heat affected zone which could limit its applications. Electron beam welding (EBW) has unique advantages over other traditional fusion welding methods due to its high-energy density, deep penetration, large depth-to-width ratio and the resulting very small heat affected zone. Optimization of EB welded joint of 2219 Al-alloy, from the yield strength, hardness and bead geometry point of view, is the topic of this study. Taguchi methodology with grey relation analysis has been applied to find the optimal welding parameters for welding of a sheet of the mentioned aluminum alloy with electron beam. The optimal welding parameters have been selected and verified experimentally.

Modeling and Numerical Simulation of Material Science, 2013

This research work is focused on simulation of laser assisted turning as a new solution for machi... more This research work is focused on simulation of laser assisted turning as a new solution for machining of hard steels. A transient, three-dimensional model was developed to predict the temperature distribution of a rotated cylindrical steel workpiece subjected to a localized heating using a moving Gaussian laser beam. In this regard, a User-Defined Function was created to overcome the problem of a moving Gaussian heat source' definition. This User-Defined Function was compiled into a finite volume software package (Fluent ® ), where three-dimensional single precision solver was used for analysis. Based on this model, simulation of the surface temperature of 32 mm diameter workpiece of AISI51 50H steel was performed as a function of time at a specific distance behind the laser beam spot, which is corresponding to 30˚ angle from the laser beam. The simulation results were compared with other published data of the same steel type where a close agreement was obtained. The verified model was used for simulation of laser assisted turning of 20 mm diameter workpiece of AISI D2 tool steel. The cutting depth, behind the laser beam, was set at a distance corresponding to 60˚ angle from the laser beam for having sufficient access for handling both laser head and cutting tool. This cutting depth was studied as a function of different lasers and machining parameters. The results indicated that the optimum parameters for successful laser-assisted turning process of the concerned steels are 800 W laser power, 5 mm laser beam spot diameter, 20 sec preheating time, 0.8 mm/sec laser scanning speed, 300 rpm rotational speed and 0.8 mm/sec feed rate. These parameters ensure easy/successful cutting of 1 mm depth in one pass without deteriorating the properties of the remaining bulk material. It can be deduced that the developed model might provide a useful tool for online process control of different steel types regardless of their physical properties and geometries.