Hakim Bouzid | École de Technologie Supérieure (original) (raw)
Uploads
Papers by Hakim Bouzid
Cambridge Scholars Publishing, 2015
Journal of Engineering Materials and Technology, 2019
The objective of this research is to describe the consequence of thermal ratcheting on the long-t... more The objective of this research is to describe the consequence of thermal ratcheting on the long-term creep property of the high-density polyethylene (HDPE) material. The thermal ratcheting phenomenon increases significantly the creep strain of HDPE. The magnitude of the creep strain of HDPE increases by 8% after just 20 thermal cycles between 28 and 50 °C. The creep modulus, which is inversely proportional to the creep strain, depletes further under thermal ratcheting. Both the properties change significantly with the number of thermal cycles. The coefficient of thermal expansion (CTE) of HDPE varies with the applied compressive load, with successive thermal cycles, and with the thermal ratcheting temperature. The impact of thermal ratcheting diminishes with an increase in initial steady creep exposure time period, but still the magnitude cumulative deformation induced is noteworthy. The magnitude of growth in creep strain drops from 8% to 2.4% when thermal ratcheting is performed a...
The International Journal of Advanced Manufacturing Technology, 2015
ABSTRACT Finite element modeling (FEM) of machining has recently become the most attractive compu... more ABSTRACT Finite element modeling (FEM) of machining has recently become the most attractive computational tool to predict and optimize metal cutting processes. High-speed computers and advanced finite element code have offered the possibility of simulating complex machining processes such as turning, milling, and drilling. The use of an accurate constitutive law is very important in any metal cutting simulation. It is desirable that a constitutive law could completely characterize the thermo-visco-plastic behavior of the machined materials at high strain rate. The most commonly used law is that of Johnson and Cook (JC) which combines the effect of strains, strain rates, and temperatures. Unfortunately, the different coefficients provided in the literature for a given material are not reliable since they affect significantly the predicted results (cutting forces, temperatures, residual stresses, etc.). In the present work, five different sets of JC are determined based on orthogonal machining tests. These five sets are then used in finite element modeling to simulate the machining behavior of Al2024-T3 alloy. The effects of these five different sets of JC constants on the numerically predicted cutting forces, chip morphology, and tool-chip contact length are the subject of a comparative investigation. It is concluded that these predicted cutting parameters are sensitive to the material constants.
Volume 1B: Extremity; Fluid Mechanics; Gait; Growth, Remodeling, and Repair; Heart Valves; Injury Biomechanics; Mechanotransduction and Sub-Cellular Biophysics; MultiScale Biotransport; Muscle, Tendon and Ligament; Musculoskeletal Devices; Multiscale Mechanics; Thermal Medicine; Ocular Biomechani..., 2013
The nucleus pulposus (NP) and the anulus fibrosus (AF) are the two main components of the interve... more The nucleus pulposus (NP) and the anulus fibrosus (AF) are the two main components of the intervertebral discs. At low deformation rates, in young and healthy adults, the NP reacts like an inviscid and incompressible fluid. Its internal pressure varies depending on the external forces acting on it. The AF surrounds the NP and, together with the vertebral endplates, they form a pressurized vessel.
Journal of Pressure Vessel Technology-transactions of The Asme, Jun 18, 2018
Bolted flange joints are widely used in the nuclear power plants and other industrial complexes. ... more Bolted flange joints are widely used in the nuclear power plants and other industrial complexes. During their assembly, it is extremely difficult to achieve the target bolt preload and tightening uniformity due to elastic interaction and criss-cross talks. In addition to the severe service loadings, the initial bolt load scatter increases the risk of leakage failure. The objective of this paper is to present an analytical model to predict the bolt tension change due to elastic interaction during the sequence of initial tightening. The proposed analytical model is based on the theory of circular beams on linear elastic foundation. The elastic compliances of the flanges, the bolts, and the gasket due to bending, twisting, and axial compression are involved in the elastic interaction and bolt load changes during tightening. The developed model can be used to optimize the initial bolt tightening to obtain a uniform final preload under minimum tightening passes. The approach is validated using finite element analysis (FEA) and experimental tests conducted on a NPS 4 class 900 weld neck bolted flange joint.
Cambridge Scholars Publishing, 2015
Journal of Engineering Materials and Technology, 2019
The objective of this research is to describe the consequence of thermal ratcheting on the long-t... more The objective of this research is to describe the consequence of thermal ratcheting on the long-term creep property of the high-density polyethylene (HDPE) material. The thermal ratcheting phenomenon increases significantly the creep strain of HDPE. The magnitude of the creep strain of HDPE increases by 8% after just 20 thermal cycles between 28 and 50 °C. The creep modulus, which is inversely proportional to the creep strain, depletes further under thermal ratcheting. Both the properties change significantly with the number of thermal cycles. The coefficient of thermal expansion (CTE) of HDPE varies with the applied compressive load, with successive thermal cycles, and with the thermal ratcheting temperature. The impact of thermal ratcheting diminishes with an increase in initial steady creep exposure time period, but still the magnitude cumulative deformation induced is noteworthy. The magnitude of growth in creep strain drops from 8% to 2.4% when thermal ratcheting is performed a...
The International Journal of Advanced Manufacturing Technology, 2015
ABSTRACT Finite element modeling (FEM) of machining has recently become the most attractive compu... more ABSTRACT Finite element modeling (FEM) of machining has recently become the most attractive computational tool to predict and optimize metal cutting processes. High-speed computers and advanced finite element code have offered the possibility of simulating complex machining processes such as turning, milling, and drilling. The use of an accurate constitutive law is very important in any metal cutting simulation. It is desirable that a constitutive law could completely characterize the thermo-visco-plastic behavior of the machined materials at high strain rate. The most commonly used law is that of Johnson and Cook (JC) which combines the effect of strains, strain rates, and temperatures. Unfortunately, the different coefficients provided in the literature for a given material are not reliable since they affect significantly the predicted results (cutting forces, temperatures, residual stresses, etc.). In the present work, five different sets of JC are determined based on orthogonal machining tests. These five sets are then used in finite element modeling to simulate the machining behavior of Al2024-T3 alloy. The effects of these five different sets of JC constants on the numerically predicted cutting forces, chip morphology, and tool-chip contact length are the subject of a comparative investigation. It is concluded that these predicted cutting parameters are sensitive to the material constants.
Volume 1B: Extremity; Fluid Mechanics; Gait; Growth, Remodeling, and Repair; Heart Valves; Injury Biomechanics; Mechanotransduction and Sub-Cellular Biophysics; MultiScale Biotransport; Muscle, Tendon and Ligament; Musculoskeletal Devices; Multiscale Mechanics; Thermal Medicine; Ocular Biomechani..., 2013
The nucleus pulposus (NP) and the anulus fibrosus (AF) are the two main components of the interve... more The nucleus pulposus (NP) and the anulus fibrosus (AF) are the two main components of the intervertebral discs. At low deformation rates, in young and healthy adults, the NP reacts like an inviscid and incompressible fluid. Its internal pressure varies depending on the external forces acting on it. The AF surrounds the NP and, together with the vertebral endplates, they form a pressurized vessel.
Journal of Pressure Vessel Technology-transactions of The Asme, Jun 18, 2018
Bolted flange joints are widely used in the nuclear power plants and other industrial complexes. ... more Bolted flange joints are widely used in the nuclear power plants and other industrial complexes. During their assembly, it is extremely difficult to achieve the target bolt preload and tightening uniformity due to elastic interaction and criss-cross talks. In addition to the severe service loadings, the initial bolt load scatter increases the risk of leakage failure. The objective of this paper is to present an analytical model to predict the bolt tension change due to elastic interaction during the sequence of initial tightening. The proposed analytical model is based on the theory of circular beams on linear elastic foundation. The elastic compliances of the flanges, the bolts, and the gasket due to bending, twisting, and axial compression are involved in the elastic interaction and bolt load changes during tightening. The developed model can be used to optimize the initial bolt tightening to obtain a uniform final preload under minimum tightening passes. The approach is validated using finite element analysis (FEA) and experimental tests conducted on a NPS 4 class 900 weld neck bolted flange joint.