Ibrahim El Fahham | Faculty Of Engineering Alexandria University (original) (raw)
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Papers by Ibrahim El Fahham
Processes, 2021
The aim of this research work is to modulate the pitch angle of both types of wind turbines based... more The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shutting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HA...
CFD Letters, 2022
The flow around road vehicle is characterized by regions of separation that affect the aerodynami... more The flow around road vehicle is characterized by regions of separation that affect the aerodynamics and performance of the vehicle due to the variations in the negative pressure zones. In this work, Computational fluid dynamics and Fluid-structure interaction models are developed to simulate the aerodynamic performance of a sedan car. An experimental live road simulation is conducted to validate the performance and the accuracy of the presented models. The experimental setup was organized on a sedan car using tufts and digital cameras for flow visualization. Four cruise speeds of 40, 60, 80, and 100 km/hr are used. At low cruise speed the FSI simulation can attain the required result for indicating the negative pressure zones, created behind the car tail and mostly close to the car body. The experimental results appear to visualize the movement of the tufts that attained a certain angle corresponding to the flow speed, which matches the distribution of negative pressure and wake are...
International Journal of Surface Science and Engineering, 2022
Processes, 2021
The aim of this research work is to modulate the pitch angle of both types of wind turbines based... more The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shutting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HA...
Processes, 2021
The aim of this research work is to modulate the pitch angle of both types of wind turbines based... more The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shut-ting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HAWT, the FLC control has successfully maintained the angular speed of the rotor. The values of tip speed ratio and coefficient of performance are reduced in order to maintain the rotor angular velocity at its rated value. On the other hand, the results showed that the torque produced by the VAWT individual blade has improved with the pitch angle control. In addition, using FLC to control the pitch angle gives enhanced output and higher Cp at low tip speed ratios. Gain schedule PI controller is also used in both HAWT and VAWT for comparative study.
ERJ. Engineering Research Journal
The present work introduces a mathematical model of a cracked pipeline conveying liquid. This mod... more The present work introduces a mathematical model of a cracked pipeline conveying liquid. This model uses governing equation of Euler-Bernoulli beam theory for a pipe conveying liquid. The crack introduced in the model is represented by two identical torsional springs and a sinusoidal excitation force was applied to one of the pipe ends for the purpose of crack detection. The model is solved numerically using MATLAB code bvp4c to solve linear, ordinary fourth order differential equations (boundary value problem) for the detection of the crack position. To group the variables in the dimensionless form, Buckingham Pi-theorem was used. The effects of the dimensionless parameters on crack position were examined. The results show that the value of dimensionless parameters of stiffness at crack and support has considerable effect on crack position. It also shows that the force amplitude and fluid flow properties has no effect on crack position which demonstrates the capacity of using the present technique with small force magnitude to avoid stress-strain problems on the pipeline and any excitation frequency can be used.
Industrial Lubrication and Tribology
Purpose The purpose of this paper is to study the effect of liner surface texture on journal bear... more Purpose The purpose of this paper is to study the effect of liner surface texture on journal bearing performance. Modeling the profile curvature of the dimples or grooves is planned for different cases of texture surface under thermo-hydrodynamic condition (THD). The aim of this paper is to determine the effect the texture surface on the performance of journal bearing and specify the optimum shape for texture dimples. Design/methodology/approach The paper was opted for an exploratory study by applying finite difference method to solve the energy equation, the heat conduction equations and the Reynolds equation numerically. The lubricant film thickness is divided to a mesh of 640,000 points. The equations were solved for each point of the mesh by using a MATLAB code. For texture shape optimization, 24 cases of different texture shapes were selected which includes elliptical, triangle and square curvature shape. Findings The paper provides theoretical insights about the effect of text...
Alexandria Dental Journal
INTRODUCTION: Cleft lip and palate (CLP) affects about 1.5 per 1000 live births (250,000 new case... more INTRODUCTION: Cleft lip and palate (CLP) affects about 1.5 per 1000 live births (250,000 new cases per year) worldwide. They can be either unilateral or bilateral, complete or incomplete. The bilateral cleft lip and palate (BCLP) deformity typically arises with a protrusive premaxilla. The nasal deformity includes deficient columella, with flared lateral alar cartilages which usually require additional surgeries to improve the nasal symmetry. NasoAlveolar Moulding (NAM) technique, aims to align the alveolus, lip, and nose properly; reduce the severity of the nasal deformity, and lengthen the columella without surgery. OBJECTIVES: The study aims to quantify the effect of NAM therapy, fabricated by CAD/CAM additive manufacturing, in the improvement of nasolabial deformity in terms of bialar width, columellar length and width in infants with complete BCLP. MATERIALS AND METHODS: Ten infants with non-syndromic BCLP (age < 1 month) were selected. Impressions were obtained. The casts obtained from the impressions were scanned using a 3D laser scanner. Designing and 3D printing of the appliances were completed. The appliances were inserted and retained using surgical tapes. Nasal stents were incorporated 60 days after the start of the treatment. Nasal measurements were obtained before treatment and at the end of treatment (after four months). RESULTS: Data was collected and statistically analyzed. After NAM therapy, there was a statistically significant increase in columellar length and a statistically significant decrease in both columellar width and bialar width. CONCLUSIONS: CAD/CAM PNAM therapy has proved its effectiveness in BCLP by showing an improvement in the columellar and bialar presurgical presentation. CAD/CAM PNAM therapy should be considered a routine procedure in the treatment protocol for BCLP.
MEJ. Mansoura Engineering Journal
rapid depletion of fossil fuels is the major concern of the industrial countries' over the last d... more rapid depletion of fossil fuels is the major concern of the industrial countries' over the last decades. Fortunately, the rapid depletion problem can be resolved using clean and cheap renewable resources like wind and solar energy. These renewable energy sources can compensate for the shortage between the growing demand and the available traditional types of energies in countries that are suffering from insufficient traditional energies. Apparently, renewable energy sources can be used in many applications which include generating cheap electricity for the deprived communities in the desert areas in addition to powering the desalination plants for producing the
Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanism... more Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanisms are not fully understood. In particular, limited attention has been paid to the generation of fatigue surface cracks under constant and cyclic load conditions. The present work focuses on the effect of load frequency on the wear behavior of a polymer with surface defects in dry sliding conditions. The defects were imposed vertical deep cracks perpendicular to the direction of sliding. Wear studies were conducted against a steel counterface at constant loads, and in cyclic loads at different frequencies. Artificial neural network (ANN) models were examined to identify one that optimally simulates wear under the applied load parameters.
A new reciprocating testing machine was designed and constructed to perform wear tests under cons... more A new reciprocating testing machine was designed and constructed to perform wear tests under constant and fluctuating loading conditions at a constant sliding speed for most of its stroke. The tribometer has the facility of changing the amplitude, mean load and the frequency of loading cycle. The wear tests can, also, be conducted under dry or wet conditions. The influence of loading mode on the wear behavior of Nylon 66 sliding against stainless steel in dry conditions was investigated on this test rig. The polymer was tested under constant and fluctuating loading conditions at two different loads and at three frequencies. Results suggested that under cyclic loading condition the polymer shows a significant increase in wear factor than those found under constant loads. The frequency of load cycle, also, has a pronounced influence on the wear behavior under cyclic load.
This paper addresses improving the ride quality of railway vehicles with sliding control of semi-... more This paper addresses improving the ride quality of railway vehicles with sliding control of semi-active secondary suspension systems using magneto-rheological (MR) dampers. A nine degree-of-freedom railway vehicle model, which includes a car body, two trucks and four wheel sets, is proposed to cope with vertical, pitch and roll motions of the car body and trucks. A Bouc-Wen model for hysteresis of MR damper is applied. The design of sliding control mode is directed toward minimizing the car body vertical acceleration to meet with the comfort ride criteria. The controlled force acquired for the MR damper is transformed to equivalent voltage to be applied to the current driver of the damper. The responses of the car body of the train vehicle with semi-active secondary suspension system integrated with MR dampers are evaluated due to periodical railway irregularities and impulse input. The performance of sliding mode control is compared to Linear Quadratic Gaussian (LQG) control. It is...
ABSTRACT Recently, Artificial Neural Networks (ANNs) have emerged as a good candidates to mathema... more ABSTRACT Recently, Artificial Neural Networks (ANNs) have emerged as a good candidates to mathematical wear models, due to their capabilities of nonlinear behavior, learning from experimental data and generalization. In the present paper the potential of using neural networks for the prediction of sliding wear properties of polymer was investigated using a measured dataset of 42 independent reciprocating sliding wear tests of Polyamide 66. The polymer was tested under various testing conditions such as applied load (constant and fluctuating), existence of surface crack and sliding media. Five different feed-forward (ff) neural network models were examined in order to find the optimum model that simulates the wear under such parameters. The optimized ANN was utilized to predict the wear rates of new input parameters, which were not tested. The quality of prediction was good when comparing the predicted and real test values. Finally, the proposed ANN was applied to four data sets adopted from previous works to evaluate its accuracy. The ANN showed good accuracy for the simulation and acceptable values of predicted wear rates. The results indicated that the well-trained neural network model is quite effective for prediction of wear response of materials within and beyond the experimental domain.
ABSTRACT In polymeric bearing applications it was found that the polymer tends to wear more quick... more ABSTRACT In polymeric bearing applications it was found that the polymer tends to wear more quickly than indicated in laboratory wear tests. The reason has been attributed to the effect of loading conditions and the generation of fatigue surface cracks. The current study investigated the effect of single imposed vertical crack in the Nylon 66 surface upon its wear behaviour in dry and water lubricated sliding conditions. The polymer was tested under different static and cyclic loading parameters. There was consistent evidence of the effect of surface crack on the wear rate under static and cyclic loading conditions.
Friction, 2014
Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanism... more Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanisms are not fully understood. In particular, limited attention has been paid to the generation of fatigue surface cracks under constant and cyclic load conditions. The present work focuses on the effect of load frequency on the wear behavior of a polymer with surface defects in dry sliding conditions. The defects were imposed vertical deep cracks perpendicular to the direction of sliding. Wear studies were conducted against a steel counterface at constant loads, and in cyclic loads at different frequencies. Artificial neural network (ANN) models were examined to identify one that optimally simulates wear under the applied load parameters.
Wear, 2011
showed a number of transverse vertical cracks, which suggested that the surface cracks play an im... more showed a number of transverse vertical cracks, which suggested that the surface cracks play an important role in surface fatigue wear.
Processes, 2021
The aim of this research work is to modulate the pitch angle of both types of wind turbines based... more The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shutting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HA...
CFD Letters, 2022
The flow around road vehicle is characterized by regions of separation that affect the aerodynami... more The flow around road vehicle is characterized by regions of separation that affect the aerodynamics and performance of the vehicle due to the variations in the negative pressure zones. In this work, Computational fluid dynamics and Fluid-structure interaction models are developed to simulate the aerodynamic performance of a sedan car. An experimental live road simulation is conducted to validate the performance and the accuracy of the presented models. The experimental setup was organized on a sedan car using tufts and digital cameras for flow visualization. Four cruise speeds of 40, 60, 80, and 100 km/hr are used. At low cruise speed the FSI simulation can attain the required result for indicating the negative pressure zones, created behind the car tail and mostly close to the car body. The experimental results appear to visualize the movement of the tufts that attained a certain angle corresponding to the flow speed, which matches the distribution of negative pressure and wake are...
International Journal of Surface Science and Engineering, 2022
Processes, 2021
The aim of this research work is to modulate the pitch angle of both types of wind turbines based... more The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shutting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HA...
Processes, 2021
The aim of this research work is to modulate the pitch angle of both types of wind turbines based... more The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shut-ting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HAWT, the FLC control has successfully maintained the angular speed of the rotor. The values of tip speed ratio and coefficient of performance are reduced in order to maintain the rotor angular velocity at its rated value. On the other hand, the results showed that the torque produced by the VAWT individual blade has improved with the pitch angle control. In addition, using FLC to control the pitch angle gives enhanced output and higher Cp at low tip speed ratios. Gain schedule PI controller is also used in both HAWT and VAWT for comparative study.
ERJ. Engineering Research Journal
The present work introduces a mathematical model of a cracked pipeline conveying liquid. This mod... more The present work introduces a mathematical model of a cracked pipeline conveying liquid. This model uses governing equation of Euler-Bernoulli beam theory for a pipe conveying liquid. The crack introduced in the model is represented by two identical torsional springs and a sinusoidal excitation force was applied to one of the pipe ends for the purpose of crack detection. The model is solved numerically using MATLAB code bvp4c to solve linear, ordinary fourth order differential equations (boundary value problem) for the detection of the crack position. To group the variables in the dimensionless form, Buckingham Pi-theorem was used. The effects of the dimensionless parameters on crack position were examined. The results show that the value of dimensionless parameters of stiffness at crack and support has considerable effect on crack position. It also shows that the force amplitude and fluid flow properties has no effect on crack position which demonstrates the capacity of using the present technique with small force magnitude to avoid stress-strain problems on the pipeline and any excitation frequency can be used.
Industrial Lubrication and Tribology
Purpose The purpose of this paper is to study the effect of liner surface texture on journal bear... more Purpose The purpose of this paper is to study the effect of liner surface texture on journal bearing performance. Modeling the profile curvature of the dimples or grooves is planned for different cases of texture surface under thermo-hydrodynamic condition (THD). The aim of this paper is to determine the effect the texture surface on the performance of journal bearing and specify the optimum shape for texture dimples. Design/methodology/approach The paper was opted for an exploratory study by applying finite difference method to solve the energy equation, the heat conduction equations and the Reynolds equation numerically. The lubricant film thickness is divided to a mesh of 640,000 points. The equations were solved for each point of the mesh by using a MATLAB code. For texture shape optimization, 24 cases of different texture shapes were selected which includes elliptical, triangle and square curvature shape. Findings The paper provides theoretical insights about the effect of text...
Alexandria Dental Journal
INTRODUCTION: Cleft lip and palate (CLP) affects about 1.5 per 1000 live births (250,000 new case... more INTRODUCTION: Cleft lip and palate (CLP) affects about 1.5 per 1000 live births (250,000 new cases per year) worldwide. They can be either unilateral or bilateral, complete or incomplete. The bilateral cleft lip and palate (BCLP) deformity typically arises with a protrusive premaxilla. The nasal deformity includes deficient columella, with flared lateral alar cartilages which usually require additional surgeries to improve the nasal symmetry. NasoAlveolar Moulding (NAM) technique, aims to align the alveolus, lip, and nose properly; reduce the severity of the nasal deformity, and lengthen the columella without surgery. OBJECTIVES: The study aims to quantify the effect of NAM therapy, fabricated by CAD/CAM additive manufacturing, in the improvement of nasolabial deformity in terms of bialar width, columellar length and width in infants with complete BCLP. MATERIALS AND METHODS: Ten infants with non-syndromic BCLP (age < 1 month) were selected. Impressions were obtained. The casts obtained from the impressions were scanned using a 3D laser scanner. Designing and 3D printing of the appliances were completed. The appliances were inserted and retained using surgical tapes. Nasal stents were incorporated 60 days after the start of the treatment. Nasal measurements were obtained before treatment and at the end of treatment (after four months). RESULTS: Data was collected and statistically analyzed. After NAM therapy, there was a statistically significant increase in columellar length and a statistically significant decrease in both columellar width and bialar width. CONCLUSIONS: CAD/CAM PNAM therapy has proved its effectiveness in BCLP by showing an improvement in the columellar and bialar presurgical presentation. CAD/CAM PNAM therapy should be considered a routine procedure in the treatment protocol for BCLP.
MEJ. Mansoura Engineering Journal
rapid depletion of fossil fuels is the major concern of the industrial countries' over the last d... more rapid depletion of fossil fuels is the major concern of the industrial countries' over the last decades. Fortunately, the rapid depletion problem can be resolved using clean and cheap renewable resources like wind and solar energy. These renewable energy sources can compensate for the shortage between the growing demand and the available traditional types of energies in countries that are suffering from insufficient traditional energies. Apparently, renewable energy sources can be used in many applications which include generating cheap electricity for the deprived communities in the desert areas in addition to powering the desalination plants for producing the
Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanism... more Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanisms are not fully understood. In particular, limited attention has been paid to the generation of fatigue surface cracks under constant and cyclic load conditions. The present work focuses on the effect of load frequency on the wear behavior of a polymer with surface defects in dry sliding conditions. The defects were imposed vertical deep cracks perpendicular to the direction of sliding. Wear studies were conducted against a steel counterface at constant loads, and in cyclic loads at different frequencies. Artificial neural network (ANN) models were examined to identify one that optimally simulates wear under the applied load parameters.
A new reciprocating testing machine was designed and constructed to perform wear tests under cons... more A new reciprocating testing machine was designed and constructed to perform wear tests under constant and fluctuating loading conditions at a constant sliding speed for most of its stroke. The tribometer has the facility of changing the amplitude, mean load and the frequency of loading cycle. The wear tests can, also, be conducted under dry or wet conditions. The influence of loading mode on the wear behavior of Nylon 66 sliding against stainless steel in dry conditions was investigated on this test rig. The polymer was tested under constant and fluctuating loading conditions at two different loads and at three frequencies. Results suggested that under cyclic loading condition the polymer shows a significant increase in wear factor than those found under constant loads. The frequency of load cycle, also, has a pronounced influence on the wear behavior under cyclic load.
This paper addresses improving the ride quality of railway vehicles with sliding control of semi-... more This paper addresses improving the ride quality of railway vehicles with sliding control of semi-active secondary suspension systems using magneto-rheological (MR) dampers. A nine degree-of-freedom railway vehicle model, which includes a car body, two trucks and four wheel sets, is proposed to cope with vertical, pitch and roll motions of the car body and trucks. A Bouc-Wen model for hysteresis of MR damper is applied. The design of sliding control mode is directed toward minimizing the car body vertical acceleration to meet with the comfort ride criteria. The controlled force acquired for the MR damper is transformed to equivalent voltage to be applied to the current driver of the damper. The responses of the car body of the train vehicle with semi-active secondary suspension system integrated with MR dampers are evaluated due to periodical railway irregularities and impulse input. The performance of sliding mode control is compared to Linear Quadratic Gaussian (LQG) control. It is...
ABSTRACT Recently, Artificial Neural Networks (ANNs) have emerged as a good candidates to mathema... more ABSTRACT Recently, Artificial Neural Networks (ANNs) have emerged as a good candidates to mathematical wear models, due to their capabilities of nonlinear behavior, learning from experimental data and generalization. In the present paper the potential of using neural networks for the prediction of sliding wear properties of polymer was investigated using a measured dataset of 42 independent reciprocating sliding wear tests of Polyamide 66. The polymer was tested under various testing conditions such as applied load (constant and fluctuating), existence of surface crack and sliding media. Five different feed-forward (ff) neural network models were examined in order to find the optimum model that simulates the wear under such parameters. The optimized ANN was utilized to predict the wear rates of new input parameters, which were not tested. The quality of prediction was good when comparing the predicted and real test values. Finally, the proposed ANN was applied to four data sets adopted from previous works to evaluate its accuracy. The ANN showed good accuracy for the simulation and acceptable values of predicted wear rates. The results indicated that the well-trained neural network model is quite effective for prediction of wear response of materials within and beyond the experimental domain.
ABSTRACT In polymeric bearing applications it was found that the polymer tends to wear more quick... more ABSTRACT In polymeric bearing applications it was found that the polymer tends to wear more quickly than indicated in laboratory wear tests. The reason has been attributed to the effect of loading conditions and the generation of fatigue surface cracks. The current study investigated the effect of single imposed vertical crack in the Nylon 66 surface upon its wear behaviour in dry and water lubricated sliding conditions. The polymer was tested under different static and cyclic loading parameters. There was consistent evidence of the effect of surface crack on the wear rate under static and cyclic loading conditions.
Friction, 2014
Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanism... more Nylon 66 has been widely used for numerous mechanical applications but its sliding wear mechanisms are not fully understood. In particular, limited attention has been paid to the generation of fatigue surface cracks under constant and cyclic load conditions. The present work focuses on the effect of load frequency on the wear behavior of a polymer with surface defects in dry sliding conditions. The defects were imposed vertical deep cracks perpendicular to the direction of sliding. Wear studies were conducted against a steel counterface at constant loads, and in cyclic loads at different frequencies. Artificial neural network (ANN) models were examined to identify one that optimally simulates wear under the applied load parameters.
Wear, 2011
showed a number of transverse vertical cracks, which suggested that the surface cracks play an im... more showed a number of transverse vertical cracks, which suggested that the surface cracks play an important role in surface fatigue wear.