Qualification: 
M.Tech, BE
s_mohankumar@blr.amrita.edu

Mohan Kumar S. is currently working as Assistant Professor (Sr. Gr.), Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Bengaluru, and pursing his Ph. D. from Visvesvaraya Technological University Belgaum, India.

Education

  • Pursuing Ph.D. in Fracture Mechanics
    VTU, Belagavi
  • 2010: M.Tech./M.E./M.S. in Machine Design
    VTU, Belagavi
  • 2008: BE
    VTU, Belagavi

Major Research Interests

  • Fracture Mechanics, Material Science, Finite Element Method, Dynamics of Machinery, Composite Materials.

Publications

Publication Type: Journal Article

Year of Publication Title

2020

S. Mohan Kumar and K, G. H., “An Investigation Of The Effects Of Solution Heat Treatment On Mechanical Properties Of Aluminium 7075 Alloys”, International Journal of Scientific & Technology Research, 2020.[Abstract]


The present works describes the Effect of heat treatment on grain size of Al 7075 alloys. The melting furnace utilized for the casting of the aluminum is an electrical resistance heater with a mechanical stirrer coated with tungsten carbide. The ageing time was varied from 1 to 20 hours in the steps of 1 hour. Mechanical characterization was performed as per ASTM standards such as tensile strength hardness tests. Results of the study reveal that Ultimate tensile strength and hardness properties are enhanced as the ageing time increases. The technique of optical microscopy was used to examine sample specimen for microstructures, and the microstructure indicated uniform particle distribution in the matrix state. Experimental results shows that there is a fall in the micro-hardness number after 14 hours of ageing due to an increase in the size of fine π precipitates as well as precipitate coarsening. The ultimate tensile strength was found to be 417.29 MPa after 20 hours of ageing, which is approximately 83.44% higher than that observed for 1 hour ageing specimen. After heat treatment, the strengthening of Al7075 alloy depends on several factors such as precipitation hardening and grain size. Furthermore to examine the fracture a scanning electron microscopy was used to examine the tested samples

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2019

S. Mohan Kumar and V. Kumar, R., “Fatigue crack prediction around non-cold worked hole”, AIP Conference Proceedings, vol. 2148, p. 030035, 2019.

2019

Shashi Kumar M. E., S. Mohan Kumar, and Ravi Kumar V., “Effect of Cryogenic Treatment on Bisphenol Based Polymer Composite on Mechanical Properties”, International Journal of Recent Technology and Engineering, vol. 8, no. 3, pp. 2413-2420., 2019.[Abstract]


Presently there are lot of materials that can be used in the fabrication of any item, so choosing a material is a major criteria. So the materials are chosen depending on the properties desired by the resulting item. The composite materials have better properties when compared with its individual components, metals and ceramics. The overall appeal of the product depends mainly on its durability, aesthetics and its final cost. Composite materials are cost effective and significantly satisfy the needs of the clients. By utilizing composite materials we can obtain high strength to weight ratio at a relatively economical cost. Moreover, they can be produced easily by basic part forming. Hybrid polymer composites have been studied of late which improves a specific property of the composite that is under question. Here a hybrid composite made of laminate of Nomex and HS glass sheets with varying percentage (1% - 2.5 %) of bisphenol dispersed in resin is prepared. The same samples were subjected to cryogenic treatment (24 hrs and 72 hrs). The results of tensile strength, flexural strength and hardness were compared for all the specimens 24 hrs cryogenic, 72hrs cryogenic and non-treated specimens. The results showed that the hardness of the cryogenic treated bisphenol based PMCs has increased with the weight percentage of Bisphenol indicating the fact that the laminates can withstand more loads at subzero temperatures The increase observed was about 3 – 4 % more in terms of BHN number. At the same time the tensile and flexural strengths have considerably reduced after treating the PMC cryogenically as the laminates becomes more brittle when treated. The tensile strength increased by about 10% approximately and the flexural strength reduced by 300%

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2019

Prakash Marimuthu K., S. Mohan Kumar, Ravi Kumar V., and Govindaraju, H. K., “Characterization of mechanical properties of epoxy reinforced with glass fiber and coconut fiber”, Materials Today: Proceedings, vol. 16, pp. 661-667, 2019.[Abstract]


The present work deals with the characterisation polymer matrix composites combining glass fiber and fiber got from coconut. The composite was prepared using hand layup process and sufficient precaution has been taken to ensure there is homogeneity. The composite is composed of 60% epoxy resin, 10% glass fiber and 30% coconut fiber. Various mechanical tests like micro hardness test, tensile strength, impact strength test has been carried out to characterise the composite. The various mechanical properties like density, micro hardness and tensile strength are affected when the coconut fibers were added. The impact strength and flexural strength of the composite increases while ultimate tensile strength decreases. The study has come up with prospective results and further research has to be done to examine the effect of fiber content, fiber orientation, loading pattern etc. Studies on corrosive wear and other tribological properties can reveal newer things, which can enable us to use the composite that is combination of epoxy and coconut fibers in newer and newer applications.

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2018

A. Ranganathan, Krishnan, P. V. Akshay, Nambiar, A. S., S. Mohan Kumar, and Ravi Kumar V., “Mechanical Characterization of AA7050-TiC Metal Matrix Composites under as Cast as condition”, Materials Today: Proceedings, vol. 5, pp. 25368-25375, 2018.[Abstract]


<p>The present works describes the mechanical properties of AA 7050 metal matrix composites reinforced with TiC. TiC particles of size 325 mesh was taken as the reinforcement material to prepare the metal matrix composites using stir casting technique. The percentage of reinforcement varied from 0 to 6% wt in steps of 2%. Mechanical characterization, such as tensile strength, hardness test, density tests were conducted as per ASTM standards. Experiment results reveal that there is an improvement in Ultimate tensile strength and hardness properties with the increase in the percentage of reinforcement. Optical microscopy technique was used to examine microstructures of the sample specimens and the microstructure revealed uniform distribution of particles and presence of reinforcements in the matrix phase. Experimental studies invokes that the 6%wt of TiC increases the tensile strength by 9% and hardness values by 10% comparing with that of as cast AA7050. Results also evident that there was a decrease in ductility and percentage of elongation with the increase in the percentage reinforcement.</p>

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2018

S. Mohan Kumar and Ravi Kumar V., “Simplified Method to Predict Fatigue Crack Growth Life by Combining Finite Element Method and Willenborg's Model”, International conference on Emerging Trends in Mechanical Engineering, vol. 2080, 2018.[Abstract]


Among various cold expansion methods, Split Sleeve Cold Expansion technique is widely used. This method induces a zone of compressive residual stresses by pulling an oversized mandrel followed by removal through the hole. An appropriate amount of compressive residual stress reduces the severity of tensile stresses acting on the components there by retarding the fatigue crack growth rate or extending the service life of the components. It has been observed that either extensive testing or special computer codes (AFGROW) are required to determine fatigue crack growth life around residual stress fields. There was no generalized procedure to predict fatigue crack growth life around residual stress fields of cold expanded holes. An attempt has been made in this work to develop a systematic, simplified method to predict fatigue crack growth life around cold expanded holes by combining finite element method and Willenborg's model. This method was in very good agreement to the classical approach and the variation of predication of fatigue crack growth was about 5.77% compared to the classical approach. The outcome of this work is the development of a systematic and simple procedure for predicting fatigue crack growth life around cold expanded fastener holes. This procedure helps in recommending appropriate inspection intervals and extending the service life of fatigue prone fastener holes.

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2018

S. Mohan Kumar and Govindaraju, H. K., “Preparation and mechanical characterization of AL7075-silicon nitride MMC’s”, International Journal of Mechanical and Production Engineering Research and Development, vol. 8, pp. 575-584, 2018.[Abstract]


The present works describes the mechanical properties of Al 7075 metal matrix composites reinforced with Si3N4. Si3N4 particles of size 325 mesh were taken as the reinforcement material to prepare the metal matrix composites by using stir casting technique. The percentage of reinforcement varied from 0 to 12% wt in steps of 3%. Mechanical characterization such as tensile strength hardness test, density tests were conducted as per ASTM standards. Experiment results reveal that there is an improvement in Ultimate tensile strength and hardness properties with the increase in the weight percentage of reinforcement. Optical microscopy technique was used to examine microstructures of the sample specimens and the microstructure revealed uniform distribution, of particles and presence of reinforcements in the matrix phase. A fractured surface on the tensile test specimen was investigated to determine the fracture mechanism by using scanning electron microscope. Experimental studies invoke that the 12%wt of Si3N4 increases the tensile strength by 7% and hardness values by 8% compared with that of as cast Al7075. Results also evident that there was a decrease in ductility and percentage of elongation with the increase in the percentage reinforcement.

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2017

D. Krishna, S. Mohan Kumar, Jyothish, J., Kumar, Aa, and Ravi Kumar V., “Electrochemical corrossion studies and mechanical characterization of al7050 metal matrix composite reinforced with ZRO2 particulate by stir casting method”, International Journal of Mechanical Engineering and Technology, vol. 8, no. 11, pp. 949-957, 2017.

2015

S. Mohan Kumar, Shashi Kumar M. E., and R. Pramod, “Finite Element Model Development for Structural Integrity of Shafts with Circumferential and Arbitrary Oriented Cracks”, Applied Mechanics and Materials, vol. 813-814, pp. 905-909, 2015.

2014

S. Mohan Kumar, R. Pramod, and Shashi Kumar M. E., “Evaluation of Fracture Toughness and Mechanical Properties of Aluminum Alloy 7075, T6 with Nickel Coating”, 12th Global Congress on Manufacturing and Management, vol. 97, pp. 178-185, 2014.[Abstract]


A study on mechanical and fracture properties, through the experimentation techniques has been carried out on a Al 7075-T6 and it coated with an Electroless Nickel deposits of 10–20 μm in coating thickness. In the recent years there has been considerable interest in the Electroless Nickel plating due to its extensive use in electronics, automobiles, aerospace and other industries. Electroless Nickel plating is a controlled autocatalytic reduction of nickel ions using suitable reducing agent such as sodium hypophosphite. ASTM Standard – E 399 for plane strain fracture toughness determination was adhered in this investigation. The results obtained, show that the EN coating can give rise to a significant improvement in the fracture behavior (performance) of the substrate and also it has shown that EN coating exhibit a very good adhesive property to the alloy material when the tensile stresses exceeding the yield strength are applied to the system and performance of these pretreatments was studied by SEM analysis.

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Publication Type: Conference Proceedings

Year of Publication Title

2018

S. Mohan Kumar, “The Effect of TiC on Microstructure and Mechanical Properties of AA 2024 MMCs”, IOP Conference Series: Materials Science and Engineering. 2018.

Publication Type: Conference Paper

Year of Publication Title

2018

S. Mohan Kumar, Raghavendra Ravikiran K., and Govindaraju, H. K., “Development of E-Glass Woven Fabric / Polyester Resin Polymer Matrix Composite and Study of Mechanical Properties”, in International Conference on Materials Manufacturing and Modelling (ICMMM - 2017), VIT, Vellore, TN, 2018, vol. 5, pp. 13367-13374.[Abstract]


E Glass fiber reinforced polymer matrix composites have been widely used as a substitute materials in automobile and aerospace applications because of their light weight characteristics and better mechanical properties. This paper describes the hand layup technique to prepare the specimen. Investigation deals with the characterization of Tensile, hardness and impact strength properties according to the ASTM standards. E Glass fibers are available in different formats, in the present research work E glass woven fabric is used as a reinforcement material and Polyester resin is used as a matrix material. The synthetic glass fiber is selected because of its excellent mechanical strength and Polyester resin is used because of its better elastic properties. Tests were carried out for a 60, 65 and 70% volume fraction of E glass woven fabric reinforced polymer matrix composites. Obtained results evident that 70% of Woven roving mat (E-glass fiber) has good mechanical properties compare to 60% volume fraction reinforced polymer matrix composite. © 2017 Elsevier Ltd.

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2017

S. Mohan Kumar, V. Kumar, R., Shashi Kumar M. E., and Govindaraju, H. K., “Mechanical characterization and fracture toughness of electroplated cadmium coating of Al -Zn alloy, T6”, in AIP Conference Proceedings, 2017, vol. 1859.[Abstract]


Fracture toughness, Hardness and Tensile Strength of the Aluminum alloy 7075-T6 coated with Cadmium with varying thickness of 10μ and 20μ were investigated. Electroplating Cadmium coating process gives excellent corrosion resistance, provides low coefficient of friction which increases the surface hardness of the material. It also provides a uniform and dense coating, in many cases, maintains surface finish as it was before plating. The specimens prepared in line with ASTM E-8M and E-399 standard were subjected to various tests. The results shows thatthe hardness of the EC coted specimens has increased by 10% and increases with increase in thickness, butthe thicker the EC coating, more brittle is the material. The Ultimate Tensile Strength also increased by 5% compared to the uncoated counterpart. There was a steep increase in plain strain fracture toughness with the increase in the coating thickness for the Aluminum 7075-T6 alloy in TL orientation. The crack growth was Unstable due to the strong adhesion between the EC coating and the alloy.

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2017

R. V. Kumar, Dileep B. P., S. Mohan Kumar, and M. V. Phanibhushana, “Effect of metal coatings on mechanical properties of aluminium alloy”, in AIP Conference Proceedings, 2017, vol. 1859.[Abstract]


This investigation mainly targeted on study of hardness and tensile properties of Al 7075 with different metal coatings like Nickel, Zinc and cadmium. Coating of these metals on Al 7075 is successfully achieved by time dependent electroplating method for different thicknesses of 10, 15 and 20 Microns. These metal coated Al-7075 specimens were tested for hardness and tensile properties according to the ASTM standards. It's found that Nickel coated alloy shows excellent hardness and tensile properties compared to Zinc and Cadmium coated alloys. 20 μm Nickel coated alloy exhibits highest hardness number of 102 HRB and Maximum Tensile Strength of 603 MPa than Zinc and Cadmium coated alloy. The microstructural studies authenticated that the coating of Nickel, zinc and cadmium on Al 7075 is homogeneous.

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2017

S. Mohan Kumar, R. Pramod, and Govindaraju, H. K., “Evaluation of Mechanical and Wear Properties of Aluminium AA430 Reinforced with SiC and Mgo”, in Materials Today: Proceedings, 2017, vol. 4, pp. 509-518.[Abstract]


Aluminum metal matrix composites (MMC's) are very widely used for several different applications like Aerospace, Automotive and Marine industries owing to their unique properties. While fabricating Hybrid MMC's using stir casting technique several technical challenges exist like achieving a uniform distribution of reinforcement within the matrix during stir casting which affects material behavior. Aluminum (AA 443.0) and SiC + MgO has been chosen as matrix and reinforcement material respectively. Experiments have been conducted by varying weight fraction of SiC + MgO (2.5%, 5% and 7.5%) while keeping all other parameters constant. An increasing trend of hardness and tensile strength with increase in weight percentage of SiC+MgO has been observed. The results also reveal that the wear rate of the test specimen's increase with the increasing load and sliding distance. The coefficient of friction slightly decreased with increasing volume content of reinforcement. © 2017 Elsevier Ltd. All rights reserved.

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2015

S. Mohan Kumar and M. E., S. K., “Modal Analysis of Annular Plate with Crack and its Effect on Natural Frequency”, in ICMME-2015, 2015.

Courses Taught

  • Engineering Drawing
  • Automotive Technology
  • Composite Materials
  • Dynamics of Machinery
  • Introduction to Finite Element Methods
  • Design of Machine Element 1
  • Design of Machine Element 2
  • Machine Drawing
  • Mechanical Vibrations

Student Guidance

Undergraduate Students

Sl. No. Name of the Student(s) Topic Status Year of Completion

 

1

 

Aditya ranganathan

Akshay krishnan p.v

Akshay s nambiar

 

COMPARATIVE STUDY AND MECHANICAL CHARACTERIZATION OF AA7050 - ZIRCONIUM OXIDE AND AA7050 - TITANIUM CARBIDE

 

Completed

 

2017

2

StephenVaidyan ,Rithesh Sumeshan, T V S Manjeeth

Portable Power Generation System by using Automobile Exhaust

Completed

2018

3

Dipin Krishna, Jyothish, Ajai Anil Kumar, Subraminian,

ELECTROCHEMICAL CORROSSION STUDIES AND MECHANICAL CHARACTERIZATION OF AL7050 METAL MATRIX COMPOSITE REINFORCED WITH ZrO2 PARTICULATE BY STIR CASTING METHOD

Completed

2018

4

SUGHOSH B.S

ARJUN P KANOOR

SAI SHIVA

SHREYAS SHETTY

PERFORMANCE ENHANCEMENT OF AN IC ENGINE

Completed

2016