Mechanics of Materials, Mechanical Engineering, Polymers and Plastics, Materials Science
10
Scopus Publications
Scopus Publications
Measurement of natural radioactivity and assessment of radiological hazard indices in soil from Tirunelveli District, Tamil Nadu, India with statistical approach T. Krishnamoorthi, Satyanarayan Bramha, S. Chandrasekaran, R. Ravichandaran, S. Sivakumar, R. Ravisankar Nuclear Analysis, 2025 The activity concentrations of naturally occurring radionuclides 238 U, 232 Th, and 40 K were determined in 31 soil samples collected from the Tirunelveli District of Tamil Nadu using grid sampling method. Gamma-ray spectrometry was applied using NaI(Tl) detector and a PC-based MCA. The mean radioactivity concentrations of 238 U, 232 Th, and 40 K were found to be 12.98 Bq.kg −1, 162.89 Bq.kg −1 and 453.04 Bq.kg −1 , respectively. The spatial map of the radionuclides was drawn and is discussed. The radiological hazards associated with soils were determined using radium equivalent activity (Ra eq ), annual gonadal dose equivalent (AGDE), activity utilization index (AUI), internal hazard index (H in ) external hazard index (H ex ) and gamma representative level index (I γ ) , were calculated. Results were discussed and compared with the internationally recommended approved values. Statistical method was used to determine the natural associations between samples and variables. This work may provide baseline data for future soil radioactive environmental monitoring and the results of the study can serve as a reference for future radiological assessments. • Activity concentrations of 238 U, 232 Th & 40 K in soils determined by gamma-ray spectrometry • The radiological hazards associated with soils are assessed using radiation indices. • Multivariate statistical tool is applied to find out relation between radioactive variables.
Integrated Study of Al-MMC Reinforced with SiC and TiO2: Advancements in Mechanical Properties, SEM Analysis, and Structural Suitability for Wind Turbine Applications R. Ravichandaran, G. Mahesh, A. Bovas Herbert Bejaxhin, N. Ramanan Journal of Machinery Manufacture and Reliability, 2024 Abstract In this study, aluminum-based metal matrix composites (MMCs) were fabricated with varying compositions of SiC and TiO2 reinforcements using the stir casting method. Three different compositions were examined: 98% Al6061 alloy, 1% SiC, and 1% TiO2; 96% Al 6061 alloy, 2% SiC, and 2% TiO2; and 94% Al alloy, 3% SiC, and 3% TiO2. These MMCs were evaluated for their mechanical behavior and microstructure in terms of tensile, flexural, and impact strength. Scanning electron microscopy (SEM) analysis revealed a uniform distribution of reinforcements, while also indicating an uneven dispersion of SiC particles within the Al matrix. Tensile testing displayed an ultimate strength of 160.06 MPa, an elongation of 6.63%, and a hardness of 96.5 for the sample with the composition of 94% Al, 3% SiC, and 3% TiO2. For the composition of 96% Al alloy, 2% SiC, and 2% TiO2, the highest flexural strength of 6.57 kN, notable impact strength of 6 J, and a hardness value of 93.68 were achieved. Atomic force microscopy (AFM) was employed to analyze surface morphology. These results demonstrate the potential of these MMCs for practical applications due to their improved properties compared to commercially available composites. The study highlights the tailored mechanical attributes of metal matrix composites, showcasing their strength, stiffness, fatigue resistance, and corrosion resistance. Such systematic analyses aid in the development of more efficient and dependable structures for wind turbine applications.
Investigation on impact and wear behavior of Al6061 (SiC + Al2O3) and Al7075 (SiC + Al2O3) hybrid composites R. Ravichandaran, S. Selvarasu, S. Gopal, R. Ramachandran Scientific and Technical Journal of Information Technologies Mechanics and Optics, 2023 The current study focuses on the properties of dry sliding characteristics and impact strength of two different aluminum alloys that were reinforced with 100 nm sized Silicon carbide (SiC) and Aluminum oxide (Al2O3) ceramic particles, for improving the mechanical properties of the final alloy with the mixing materials characteristics. Stir casting method is adopted for fabricating the composites, matrix being Al6061 and Al7075, utilizing three distinct reinforcement ratios. In order to improve the mechanical properties and increase resistance to wear, tear, and shear, SiC and Al2O3 are utilized as reinforcing elements. Following the creation of the composite matrices, their physical and mechanical behaviors are examined in accordance with ASTM standards, and a comparison between the hybrid composites made of Al6061 and Al7075 is then completed. Comparison of the obtained samples showed that the Al7075 (12 % SiC + 6 % Al2O3) alloy exhibits characteristics with exceptional tribological and mechanical characteristics. The studied alloy can be used in the automotive industry, for example, in the production of pistons, connecting rods, due to the minimum degree of wear and variable thermal expansion coefficient.
Comprehensive characterization of Echinochloa frumentacea leaf fiber as a novel reinforcement for composite applications Ravichandaran Rathinavelu, Baskara Sethupathi Paramathma Polymer Composites, 2022 Abstract The promising characteristic features of some natural plant fibers identified has driven many scientists/researchers to seek more plant fibers with good mechanical, thermal, tensile and surface properties. Plant fibers with such characteristics along with their renewable, degradable, eco‐friendly, cost‐effective nature could make them a probable competitor against synthetic ones, in many aspects. Since identification of novel plant fibers with superior quality is necessary at the moment in order to reduce the harmful effects of synthetic materials. Since the current study recognized a novel natural plant fiber from Echinochloa frumentacea and analyzed its efficiency for composite fabrication through various characterization practices. It was found from the physico‐chemical investigation that the fiber encloses with good crystallinity index (35.87%), cellulose content (60.31%) and relatively low density (896 ± 32.14 kg/m 3 ). In fact, EFLF's has admirable thermal stability (330°C) and tensile strength (204.32 ± 14.25 MPa) designated its suitability for temperature varying environments. Conversely, the proposed fiber ensures good fiber‐matrix adhesion in spite of good surface roughness and decreased microfibrillar angle (9.27 ± 0.31°), noted by surface analysis. Hence, the current study recommends further utilization of EFLF as a reinforcing material with high specific qualities and low environmental effect, for composite manufacturing.
Suitability examination of a new cellulosic fiber extracted from the stem of Ventilago maderaspatana plant as polymer composite reinforcement Ravichandaran Rathinavelu, Eakambaram Arumugam, Baskara Sethupathi Paramathma Polymer Composites, 2022 Abstract This article is designed to examine the aptness of Ventilago maderaspatana fiber (VMF) as reinforcement in polymer composites. A significant quantity of cellulose fraction (56.12 ± 5.42 wt%) in the VMF was estimated via chemical analysis. The X‐ray diffraction analysis identified the presence of cellulose type‐I and peak cellulose type‐IV in the VMF, and it quantified the crystallinity index (25.88%) and crystalline size (26.12 nm) of the VMF. Various chemical functional groups in the VMF were categorized with the help of Fourier‐transform infrared spectroscopic analysis. The thermal degradation behavior of the VMF was investigated with the help of thermogravimetric analysis, and it determined the thermal stability (200°C) and kinetic activation energy (62.46 kJ/mol) of VMF. The scanning electron microscopic and energy dispersive X‐ray spectroscopic analysis revealed the existence of contaminations, hemicellulose and lignin on the outer layer of VMF, and it was confirmed by atomic force microscopic analysis. The lower density (1236 ± 18.42 kg/m 3 ) and better tensile strength (383.7 ± 16.07 MPa) of the VMF enabled the possibility of use as reinforcement in fiber reinforced plastics.
Extraction and Characterization of Natural Cellulose Fibers from the Buxus sempervirens for Composite Reinforcement Ravichandaran Rathinavelu, Eakambaram Arumugam, Baskara Sethupathi Paramathma Journal of Natural Fibers, 2022 The ecological conservation in the current global scenario has led scholars to use natural fibers as a reinforcement in composites that resulted in the exploration of new natural cellulose fibers. This research investigates the extraction and characterization of natural cellulose fibers from the stems of Buxus sempervirens (BS) plants, which are used to produce various products. Manual retting of stems resulted in Buxus sempervirens fibers production, which was then evaluated for their physical, chemical, thermal, crystallographic, and morphological characteristics. The results elucidated that BS fibers had a cellulose percentage of 51.78%, 18.42% hemicellulose, and 17.36% lignin. The Fourier Transform Infrared Spectroscopy results validated the chemical constituents. Crystallographic investigations utilizing X-Ray diffraction revealed a crystalline index of 18.05%. The thermogravimetric analysis of BS fibers showed char residue of 33% and a maximum degradation temperature of 263°C. The BS fibers revealed good surface interlocks that can be inferred from Scanning Electron Microscope. Thus, from the results compared with other natural fibers, we demonstrate that Buxus sempervirens fibers can be effectively used as reinforcement in polymeric composites.
Mixed-mode I/III fracture characterization of aluminum alloy R. Ravichandaran, G. Thanigaiyarasu Advanced Materials Research, 2014 Aluminum alloy 5083 is taken for the study of fracture parameters in mixed-mode I/III. Three point bend specimens with load inclination and notch inclination are fabricated and precracked. They are tested with various inclination angles and for two different thicknesses. The results are analyzed and found that the fracture toughness decreases for larger inclination angles. Also, it is found that the thinner specimens are found to be tougher than the thicker specimens. Material and methods Symmetrical three-point bend cracked specimens have been used extensively in fracture mechanics to study mode I fracture properties because they are one of the standard types of specimens used in the ASTM codes for determining the fracture toughness JIc..In the mixed-mode I/III fracture, there is only a limited amount of experimental work done so far. The observations on combined mode I - mode III fracture have been very scarce and there is no general agreement among researchers on the effect of the addition of a mode III component to pure mode I loading. Limited study (Avci et al 2005 [, Kamat and Hirth 1996 [) has been done on bend specimens subjected to mixed-mode I/III when compared to the mode I case, i.e., a center-loaded specimen.
