Papers by Dr. Pradeep Johnson
Matéria (Rio de Janeiro) , 2024
Friction Stir Welding (FSW) is a solid-state joining technique which attained significant awarene... more Friction Stir Welding (FSW) is a solid-state joining technique which attained significant awareness due to its ability to produce high-quality welds without melting the base materials. The distribution of temperature across the plates during the FS Welding process is critical for determining the microstructural evolution, mechanical properties, and residual stresses of the welded joints. This research article aims to develop a comprehensive finite element (FE) model to predict the temperature distribution during the FS Welding process. The FE model incorporates the coupled thermo-mechanical behaviour of the FS Welding process, considering the heat generation and temperature-dependent material characteristics, plastic deformation and friction, and also the effect of tool geometry. The model is validated using experimental measurements, and the results obtained shows the simulated values representing the highest temperature obtained with respect to experimental values are within an error percentage of 3% from the experimental values and thereby validating the FEA procedure.
Overview of Ample Investigation on Renewable Energy Sources: Types of Sources, Tasks, and Implications: A Review
Lecture notes in mechanical engineering, 2024
Additive Manufacturing: Revolutionizing Modern Manufacturing Technology
As environmental awareness increases, organizations are more concerned about environmental sustai... more As environmental awareness increases, organizations are more concerned about environmental sustainability[1] and conducting several environmental stability identification tests on their products. In this paper our aim is to evaluate the environmental impact of some important sub-assemblies of an 0.5 hp pump during extraction and production of raw materials, manufacture of main parts, assembly and use of the product, disposal and recycle of scrap after end of life, with the help of solid works sustainability software which provides a means to select materials which have lesser environmental impact and make the product eco friendly.
Performance Evaluation of Optical D Flip Flop Built Sequential Circuits
2022 6th International Conference on Electronics, Communication and Aerospace Technology, Dec 1, 2022
Performance Evaluation of Optical D Flip Flop Built Sequential Circuits
2022 6th International Conference on Electronics, Communication and Aerospace Technology
Journal of materials research and technology, May 1, 2020
In this investigation, Friction stir welding (FSW) was performed to join 3 mm-thick AISI 321 stai... more In this investigation, Friction stir welding (FSW) was performed to join 3 mm-thick AISI 321 stainless steel sheets. The rectangular sheets of size 100 mm × 50 mm were butt joined to contemplate the impact of tool rotational speeds for the steady welding traverse speed of 55 mm/min, axial force of 13 kN and tool tilt angle of 1.5 •. The present assessment aims to correlate the relationship between the weld joint properties and important FSW parameter, the tool rotational speed. Microstructural investigation on the FS welded joints was performed using optical microscope and scanning electron microscopy (SEM). Transverse tensile test was undertaken to ascertain the quality and strength of the welded joints such as yield strength, ultimate tensile strength, etc. The microstructural features reveal evolution of fine equiaxed austenite grain structures in the weld stir zone dominated by discontinuous dynamic recrystallization mechanism. The weld joints fabricated at 500 rpm and 700 rpm had significantly better strength about 88% and 93% compared to the base metal. Subsequently, the hardness of the weld stir zones was significantly greater than the hardness of the base metal. All the welds fractured at a distance to that of the weld stir zone and dimple structures were observed at the fracture locations.
Journal of Materials Research and Technology, 2020
In this investigation, Friction stir welding (FSW) was performed to join 3 mm-thick AISI 321 stai... more In this investigation, Friction stir welding (FSW) was performed to join 3 mm-thick AISI 321 stainless steel sheets. The rectangular sheets of size 100 mm × 50 mm were butt joined to contemplate the impact of tool rotational speeds for the steady welding traverse speed of 55 mm/min, axial force of 13 kN and tool tilt angle of 1.5 •. The present assessment aims to correlate the relationship between the weld joint properties and important FSW parameter, the tool rotational speed. Microstructural investigation on the FS welded joints was performed using optical microscope and scanning electron microscopy (SEM). Transverse tensile test was undertaken to ascertain the quality and strength of the welded joints such as yield strength, ultimate tensile strength, etc. The microstructural features reveal evolution of fine equiaxed austenite grain structures in the weld stir zone dominated by discontinuous dynamic recrystallization mechanism. The weld joints fabricated at 500 rpm and 700 rpm had significantly better strength about 88% and 93% compared to the base metal. Subsequently, the hardness of the weld stir zones was significantly greater than the hardness of the base metal. All the welds fractured at a distance to that of the weld stir zone and dimple structures were observed at the fracture locations.
Experimental investigation of pineapple fiber and calcinated poultry egg shell powder epoxy composites
Biomass Conversion and Biorefinery
Strain hardening behaviour of friction stir welded magnesium alloy
Materials Today: Proceedings
One Dimensional Analysis Program for Scramjet and Ramjet Flowpaths
This book is intended for aerospace engineering students as well as professional aerospace engine... more This book is intended for aerospace engineering students as well as professional aerospace engineers who are interested in Scramjet and Ramjet propulsion technology. Conceptual analysis are an important part of Scramjet/Ramjet propulsion technology and this book talks about the basics of Scramjet and Ramjet propulsion as well as one-dimensional analyis program. Plenty of MATLAB, Fortran, CFD analysis and thermodynamic analysis is also provided for the student/engineers. This book is a must for any aerospace engineer who wants an introductory material for Scramjet and Ramjet propulsion along with analysis program. Rohan M Ganapathy, Prof. Pradhapraj and Prof. Pradeep Johnson discuss the various scenarios for Scramjet propulsion and flowpath analysis program in this book.
Advances in Materials Science and Engineering
The enhancement of composites’ mechanical characteristics (tensile, compressive, and hardness) is... more The enhancement of composites’ mechanical characteristics (tensile, compressive, and hardness) is a constant demand for technological advancement. The stir casting process is used to make the hybrid aluminium alloy metal matrix composites Al 6061-SiC-AlN in our present study. To create mechanical qualities such as tensile, compressive, and hardness, silicon carbide and aluminium nitride (both 3% and 6%) were utilized as the reinforcement. The tensile strength, compressive strength, and hardness of the Al 6061-SiC-AlN hybrid composites samples were determined. The tensile, compressive, and hardness parameters of Al 6061-SiC-AlN hybrid composites are estimated and evaluated to those of the matrix Al 6061 alloy. With the inclusion of silicon carbide and AlN nanoparticles, the tensile strength, compressive strength, and hardness increased from 328 to 385 MPa, 145 to 178 Mpa, and 302 to 724 VHN, respectively.
Parametric optimization of explosive welding process on nickel-titanium alloys
Materials Today: Proceedings
Microstructure and mechanical properties of friction stir welded AISI321 stainless steel
Journal of Materials Research and Technology
Friction Stir Welding Of 321Stainless Steel Plates by Tungsten Lanthanum Tool and Its Joint Analyses
Materials Today: Proceedings
Design of Magnetoplasmadynamic Thruster Incorporating Friction Stir Welding Technique
54th AIAA Aerospace Sciences Meeting, 2016
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Papers by Dr. Pradeep Johnson