Ravindra Saxena | Sant Longowal Institute of Engineering and Technology (original) (raw)

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Papers by Ravindra Saxena

Nucleation and Atmospheric Aerosols, 2018

The aim of this study to developed a 3-D thermal finite element model for dissimilar material wel... more The aim of this study to developed a 3-D thermal finite element model for dissimilar material welding of AISI-304 stainless steel and copper. Welding of similar material is widely studied using experimental and numerical methods but the problem becomes trivial for the welding of dissimilar materials especially in ferrous and nonferrous materials. Finite element analysis of dissimilar material welding is a cost-effective method for the understanding and analysis of the process. The finite element analysis has been performed to predict the heat affected zone and temperature distribution in AISI-304 stainless steel and copper dissimilar weldment using MSC Marc 2017®. Due to the difference in physical properties of these materials the behavior of heat affected zone and temperature distribution are perceived to be different. To verify the accuracy of the thermal finite element model, the welding process was simulated with butt-welded joints having same dimensions and parameters from Attarha and Far [1]. It is found from the study that the heat affected zone is larger in copper weld pads than in AISI 304 stainless steel due to large difference in thermal conductivity of these two weld pads.

In recent years, the axle loads on railway cars is increasing due to increased transport of the g... more In recent years, the axle loads on railway cars is increasing due to increased transport of the goods and faster infrastructural growth. The rail wheels are subjected to high contact stresses of alternating magnitude due to rolling action of the wheels under these loads. The rail wheels should be able to sustain these variable loading for reasonably infinite life. Accidents due to fracture of rail wheels affects the safety of railway facility. Therefore more attention is paid to the quality of rail-wheel. The rail wheels are found to fail predominantly due to fatigue under these variable loadings whereas other modes of failure are damage to railway bogie, suspension failure and in some cases derailment of the vehicle. After all the advancements in design, materials and non-destructive inspection, the fatigue propagation and failure due to damage of railway components remains an important issue for safety engineering in railways. In this work, an attempt is made to investigate the occurrence of stresses in rail-wheel assembly due to high contact loads at the assembly points. The study involves the determination of equivalent stress (von-Mises), strain, safety factor using finite element method on ANSYS® 2016. An appropriate understanding of these mechanisms needs in depth knowledge of physical interactions between rail and wheel. The rail wheel assembly is assumed to operate under the designed load. The Goodman mean stress correction theory is used to obtain results. The results on the fatigue life are presented which are assumed to depend on these factors.

Lecture notes in mechanical engineering, 2020

Journal of physics, Jul 1, 2019

Materials Today: Proceedings, 2020

Journal of The Brazilian Society of Mechanical Sciences and Engineering, Mar 1, 2021

The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stai... more The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stainless steel and oxygen-free copper (C10200) sheets, 1.00 mm thick. A dissimilar weld joint is fabricated using the gas tungsten arc welding process. Due to the large differences in material properties, there is uneven partitioning of the heat at the joint interface in dissimilar welding. Consequently, the welding arc was offset toward the copper side. The weldments are prepared using different offsetting distances for the welding arc. The finite element (FE) formulation is developed to study the thermal behavior due to welding arc offsetting in the dissimilar weldment. In this study, the offsetting distance is considered within the range of 0.0–3.0 mm. The Time–Temperature trends and the resulting temperature contours over the domain obtained using FE analysis are compared vis-a-vis experimental observation to find the optimum values of the offset for the welding arc for this combination. The analysis revealed that AISI 304 Stainless Steel is prone to melting at lower values of the offset as compared to copper which reflects the opposite trend in higher values of offset.

International Journal for Computational Methods in Engineering Science and Mechanics, Mar 6, 2023

Materials Today: Proceedings, 2019

High velocity contact-impact problems are of great interest in industries related to aerospace, m... more High velocity contact-impact problems are of great interest in industries related to aerospace, mechanical and civil engineering. Ductile fracture often occurs in such applications. Taylor rod impact tests are used as experimental and numerical tests for determining the mechanical behaviour of materials subjected to high strain rates. At sufficiently high velocities, a significant plastic deformation leading to fracture is observed. In this paper, ductile fracture in Taylor rod made of AISI1045 steel is simulated using a continuum damage mechanics model. Simulations are performed for the velocity of 250 and 300 m/s. It is observed that, at lower velocities, tensile cracks are observed at the outer edge of the impact surface. On the other hand, at higher velocities, the fracture is observed at the central axis (confined fracture) as well as at the outer edge leading to fragmentation. Both the results are consistent with the experimental results available in the literature.

Journal of Mechanical Science and Technology

Applied and Computational Mechanics, 2022

Journal of the Brazilian Society of Mechanical Sciences and Engineering

The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stai... more The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stainless steel and oxygen-free copper (C10200) sheets, 1.00 mm thick. A dissimilar weld joint is fabricated using the gas tungsten arc welding process. Due to the large differences in material properties, there is uneven partitioning of the heat at the joint interface in dissimilar welding. Consequently, the welding arc was offset toward the copper side. The weldments are prepared using different offsetting distances for the welding arc. The finite element (FE) formulation is developed to study the thermal behavior due to welding arc offsetting in the dissimilar weldment. In this study, the offsetting distance is considered within the range of 0.0–3.0 mm. The Time–Temperature trends and the resulting temperature contours over the domain obtained using FE analysis are compared vis-a-vis experimental observation to find the optimum values of the offset for the welding arc for this combination. The analysis revealed that AISI 304 Stainless Steel is prone to melting at lower values of the offset as compared to copper which reflects the opposite trend in higher values of offset.

AIP Conference Proceedings

The aim of this study to developed a 3-D thermal finite element model for dissimilar material wel... more The aim of this study to developed a 3-D thermal finite element model for dissimilar material welding of AISI-304 stainless steel and copper. Welding of similar material is widely studied using experimental and numerical methods but the problem becomes trivial for the welding of dissimilar materials especially in ferrous and nonferrous materials. Finite element analysis of dissimilar material welding is a cost-effective method for the understanding and analysis of the process. The finite element analysis has been performed to predict the heat affected zone and temperature distribution in AISI-304 stainless steel and copper dissimilar weldment using MSC Marc 2017®. Due to the difference in physical properties of these materials the behavior of heat affected zone and temperature distribution are perceived to be different. To verify the accuracy of the thermal finite element model, the welding process was simulated with butt-welded joints having same dimensions and parameters from Attarha and Far [1]. It is found from the study that the heat affected zone is larger in copper weld pads than in AISI 304 stainless steel due to large difference in thermal conductivity of these two weld pads.

Materials Today: Proceedings, 2020

Journal of Pressure Vessel Technology, 2018

Submerged arc welding of SA 516 grade 60 pressure vessel grade steel was conducted with different... more Submerged arc welding of SA 516 grade 60 pressure vessel grade steel was conducted with different heat plate thicknesses and the influence of cooling rate on microstructure, Vickers hardness, and impact toughness of heat affected zone (HAZ) of weldment was systematically investigated. Weld cooling rates vary with change in heat input or variation in plate thickness of base metal. Results showed that thin plates accumulate the heat, which cause grain coarsening and loss of acicular ferrite (AF) microstructure, which is further responsible for lower impact strength of welded joint. It is deemed that faster cooling rates due to heat sink in thickness direction with thick plates cause high percentage of AF with finer grain and enhanced hardness values. Improved impact strength with thick plates with same heat input signifies that supplying heat more than required to thin plates may cause microstructural deterioration and responsible for impact strength loss of weldments. Test demonstrat...

Volume 4: Processes, 2018

In the present work, Stress corrosion cracking (SCC) and its mechanical behavior are presented. S... more In the present work, Stress corrosion cracking (SCC) and its mechanical behavior are presented. SCC represents complex behavior due to electrochemical and mechanical interaction. Damage models are proposed to predict crack initiation time for stainless steel under constant load using the concept of continuum damage mechanics to show incremental damage accumulation which finally leads to failure of the material. Two damage models applicable to prediction of damage in SCC, Lemaitre damage model and damage driving force model proposed by Kamaya are compared. The comparative study of the results obtained by these damage models shows that in Lemaitre damage law cracks initiate randomly while in damage driving force model the stress concentration occurs around the periphery of damaged element results in increased damage force. The study can be used to estimate the crack initiation time in SCC under corrosive atmosphere.

International Journal of Engineering, Science and Technology

In the present investigation, the influence of joint design on the microstructure and the mechani... more In the present investigation, the influence of joint design on the microstructure and the mechanical properties of SAF 2205 duplex stainless steel welds are reported. Plates with two different joint designs were welded using the gas tungsten arc welding process. To investigate the sole effect of joint design, the joints were designed in such a way that both joints have similar groove volumes. The weldments were investigated for microstructural characterization, ferrite content, and microhardness study; later, they were subjected to Charpy V-notch impact test, transverse tensile test, and fatigue testing in order to investigate the mechanical performance. Both the weld joints were able to achieve 100% joint efficiency in view of the transverse tensile test. Different weld joint configurations demonstrated the influence of the differential heat dissipation characteristics of the joints, evident from different morphological features revealed through optical microscopy of the weldment. ...

In deep drawing operation, friction plays an important role. Friction also influences the stresse... more In deep drawing operation, friction plays an important role. Friction also influences the stresses and strains in the work-piece material and, hence, the quality of the product. In sheet metal forming simulations, the Coulomb’ friction model is often used. The friction coefficient is dependent on contact pressure and/or deformation of the sheet material. When two surfaces come in contact, the surface texture of a material changes due to the combination of normal loading and stretching. A recently proposed friction model based on the surface changes on the micro-scale is incorporated into an in-house FE deep drawing code to find its effect. The results show a realistic distribution of the coefficient of friction depending on the local process conditions.

Sixth International Conference on Advances in Mechanical and Robotics Engineering - AMRE 2017, 2017

Nucleation and Atmospheric Aerosols, 2018

The aim of this study to developed a 3-D thermal finite element model for dissimilar material wel... more The aim of this study to developed a 3-D thermal finite element model for dissimilar material welding of AISI-304 stainless steel and copper. Welding of similar material is widely studied using experimental and numerical methods but the problem becomes trivial for the welding of dissimilar materials especially in ferrous and nonferrous materials. Finite element analysis of dissimilar material welding is a cost-effective method for the understanding and analysis of the process. The finite element analysis has been performed to predict the heat affected zone and temperature distribution in AISI-304 stainless steel and copper dissimilar weldment using MSC Marc 2017®. Due to the difference in physical properties of these materials the behavior of heat affected zone and temperature distribution are perceived to be different. To verify the accuracy of the thermal finite element model, the welding process was simulated with butt-welded joints having same dimensions and parameters from Attarha and Far [1]. It is found from the study that the heat affected zone is larger in copper weld pads than in AISI 304 stainless steel due to large difference in thermal conductivity of these two weld pads.

In recent years, the axle loads on railway cars is increasing due to increased transport of the g... more In recent years, the axle loads on railway cars is increasing due to increased transport of the goods and faster infrastructural growth. The rail wheels are subjected to high contact stresses of alternating magnitude due to rolling action of the wheels under these loads. The rail wheels should be able to sustain these variable loading for reasonably infinite life. Accidents due to fracture of rail wheels affects the safety of railway facility. Therefore more attention is paid to the quality of rail-wheel. The rail wheels are found to fail predominantly due to fatigue under these variable loadings whereas other modes of failure are damage to railway bogie, suspension failure and in some cases derailment of the vehicle. After all the advancements in design, materials and non-destructive inspection, the fatigue propagation and failure due to damage of railway components remains an important issue for safety engineering in railways. In this work, an attempt is made to investigate the occurrence of stresses in rail-wheel assembly due to high contact loads at the assembly points. The study involves the determination of equivalent stress (von-Mises), strain, safety factor using finite element method on ANSYS® 2016. An appropriate understanding of these mechanisms needs in depth knowledge of physical interactions between rail and wheel. The rail wheel assembly is assumed to operate under the designed load. The Goodman mean stress correction theory is used to obtain results. The results on the fatigue life are presented which are assumed to depend on these factors.

Lecture notes in mechanical engineering, 2020

Journal of physics, Jul 1, 2019

Materials Today: Proceedings, 2020

Journal of The Brazilian Society of Mechanical Sciences and Engineering, Mar 1, 2021

The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stai... more The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stainless steel and oxygen-free copper (C10200) sheets, 1.00 mm thick. A dissimilar weld joint is fabricated using the gas tungsten arc welding process. Due to the large differences in material properties, there is uneven partitioning of the heat at the joint interface in dissimilar welding. Consequently, the welding arc was offset toward the copper side. The weldments are prepared using different offsetting distances for the welding arc. The finite element (FE) formulation is developed to study the thermal behavior due to welding arc offsetting in the dissimilar weldment. In this study, the offsetting distance is considered within the range of 0.0–3.0 mm. The Time–Temperature trends and the resulting temperature contours over the domain obtained using FE analysis are compared vis-a-vis experimental observation to find the optimum values of the offset for the welding arc for this combination. The analysis revealed that AISI 304 Stainless Steel is prone to melting at lower values of the offset as compared to copper which reflects the opposite trend in higher values of offset.

International Journal for Computational Methods in Engineering Science and Mechanics, Mar 6, 2023

Materials Today: Proceedings, 2019

High velocity contact-impact problems are of great interest in industries related to aerospace, m... more High velocity contact-impact problems are of great interest in industries related to aerospace, mechanical and civil engineering. Ductile fracture often occurs in such applications. Taylor rod impact tests are used as experimental and numerical tests for determining the mechanical behaviour of materials subjected to high strain rates. At sufficiently high velocities, a significant plastic deformation leading to fracture is observed. In this paper, ductile fracture in Taylor rod made of AISI1045 steel is simulated using a continuum damage mechanics model. Simulations are performed for the velocity of 250 and 300 m/s. It is observed that, at lower velocities, tensile cracks are observed at the outer edge of the impact surface. On the other hand, at higher velocities, the fracture is observed at the central axis (confined fracture) as well as at the outer edge leading to fragmentation. Both the results are consistent with the experimental results available in the literature.

Journal of Mechanical Science and Technology

Applied and Computational Mechanics, 2022

Journal of the Brazilian Society of Mechanical Sciences and Engineering

The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stai... more The present study investigates the effect of welding arc offsetting on weldments of AISI 304 stainless steel and oxygen-free copper (C10200) sheets, 1.00 mm thick. A dissimilar weld joint is fabricated using the gas tungsten arc welding process. Due to the large differences in material properties, there is uneven partitioning of the heat at the joint interface in dissimilar welding. Consequently, the welding arc was offset toward the copper side. The weldments are prepared using different offsetting distances for the welding arc. The finite element (FE) formulation is developed to study the thermal behavior due to welding arc offsetting in the dissimilar weldment. In this study, the offsetting distance is considered within the range of 0.0–3.0 mm. The Time–Temperature trends and the resulting temperature contours over the domain obtained using FE analysis are compared vis-a-vis experimental observation to find the optimum values of the offset for the welding arc for this combination. The analysis revealed that AISI 304 Stainless Steel is prone to melting at lower values of the offset as compared to copper which reflects the opposite trend in higher values of offset.

AIP Conference Proceedings

The aim of this study to developed a 3-D thermal finite element model for dissimilar material wel... more The aim of this study to developed a 3-D thermal finite element model for dissimilar material welding of AISI-304 stainless steel and copper. Welding of similar material is widely studied using experimental and numerical methods but the problem becomes trivial for the welding of dissimilar materials especially in ferrous and nonferrous materials. Finite element analysis of dissimilar material welding is a cost-effective method for the understanding and analysis of the process. The finite element analysis has been performed to predict the heat affected zone and temperature distribution in AISI-304 stainless steel and copper dissimilar weldment using MSC Marc 2017®. Due to the difference in physical properties of these materials the behavior of heat affected zone and temperature distribution are perceived to be different. To verify the accuracy of the thermal finite element model, the welding process was simulated with butt-welded joints having same dimensions and parameters from Attarha and Far [1]. It is found from the study that the heat affected zone is larger in copper weld pads than in AISI 304 stainless steel due to large difference in thermal conductivity of these two weld pads.

Materials Today: Proceedings, 2020

Journal of Pressure Vessel Technology, 2018

Submerged arc welding of SA 516 grade 60 pressure vessel grade steel was conducted with different... more Submerged arc welding of SA 516 grade 60 pressure vessel grade steel was conducted with different heat plate thicknesses and the influence of cooling rate on microstructure, Vickers hardness, and impact toughness of heat affected zone (HAZ) of weldment was systematically investigated. Weld cooling rates vary with change in heat input or variation in plate thickness of base metal. Results showed that thin plates accumulate the heat, which cause grain coarsening and loss of acicular ferrite (AF) microstructure, which is further responsible for lower impact strength of welded joint. It is deemed that faster cooling rates due to heat sink in thickness direction with thick plates cause high percentage of AF with finer grain and enhanced hardness values. Improved impact strength with thick plates with same heat input signifies that supplying heat more than required to thin plates may cause microstructural deterioration and responsible for impact strength loss of weldments. Test demonstrat...

Volume 4: Processes, 2018

In the present work, Stress corrosion cracking (SCC) and its mechanical behavior are presented. S... more In the present work, Stress corrosion cracking (SCC) and its mechanical behavior are presented. SCC represents complex behavior due to electrochemical and mechanical interaction. Damage models are proposed to predict crack initiation time for stainless steel under constant load using the concept of continuum damage mechanics to show incremental damage accumulation which finally leads to failure of the material. Two damage models applicable to prediction of damage in SCC, Lemaitre damage model and damage driving force model proposed by Kamaya are compared. The comparative study of the results obtained by these damage models shows that in Lemaitre damage law cracks initiate randomly while in damage driving force model the stress concentration occurs around the periphery of damaged element results in increased damage force. The study can be used to estimate the crack initiation time in SCC under corrosive atmosphere.

International Journal of Engineering, Science and Technology

In the present investigation, the influence of joint design on the microstructure and the mechani... more In the present investigation, the influence of joint design on the microstructure and the mechanical properties of SAF 2205 duplex stainless steel welds are reported. Plates with two different joint designs were welded using the gas tungsten arc welding process. To investigate the sole effect of joint design, the joints were designed in such a way that both joints have similar groove volumes. The weldments were investigated for microstructural characterization, ferrite content, and microhardness study; later, they were subjected to Charpy V-notch impact test, transverse tensile test, and fatigue testing in order to investigate the mechanical performance. Both the weld joints were able to achieve 100% joint efficiency in view of the transverse tensile test. Different weld joint configurations demonstrated the influence of the differential heat dissipation characteristics of the joints, evident from different morphological features revealed through optical microscopy of the weldment. ...

In deep drawing operation, friction plays an important role. Friction also influences the stresse... more In deep drawing operation, friction plays an important role. Friction also influences the stresses and strains in the work-piece material and, hence, the quality of the product. In sheet metal forming simulations, the Coulomb’ friction model is often used. The friction coefficient is dependent on contact pressure and/or deformation of the sheet material. When two surfaces come in contact, the surface texture of a material changes due to the combination of normal loading and stretching. A recently proposed friction model based on the surface changes on the micro-scale is incorporated into an in-house FE deep drawing code to find its effect. The results show a realistic distribution of the coefficient of friction depending on the local process conditions.

Sixth International Conference on Advances in Mechanical and Robotics Engineering - AMRE 2017, 2017