Browsing by Author "Muralidhar, M."

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A Numerical Study on Coconut Inflorescence Stem-Fiber-Reinforced Panels Subjected to Tensile Load, Compressive Load, and Flexural Load
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Muralidhar, M.; Mahadevaiah, R.R.; Parshuram, K.R.B.; Hiremath, P.
Natural-fiber-reinforced composites are attracting an increasing amount of interest, and they are becoming more popular as a replacement for synthetic-fiber-reinforced composites. Natural-fiber-reinforced composites are important as a potential building material due to their lightweight nature, strength, and favorable qualities, which include eco-friendliness, non-toxicity, and biodegrad-ability. Natural fibers such as hemp fibers, jute fibers, banana fibers, coconut fibers, sisal fibers, bamboo fibers, areca nut fibers, and kenaf fibers have been used for making composite panels be-cause of their strength-to-weight ratio. Coconut inflorescence stem fibers are considered for our study. Coconut inflorescence stem-reinforced composite panels are often subjected to tensile load, compression load, and flexural load. Tensile strength, compressive strength, and flexural strength play a vital role when these panels are subjected to service loads. In this context, finite element analysis (FEA) is carried out on coconut inflorescence stem-reinforced panels subjected to tensile load, compressive load, and flexural load. A linear analysis is performed for the mechanical properties by using ANSYS workbench 2021 R1. A coconut inflorescence stem-reinforced composite specimen with the dimensions 280 mm × 25 mm × 3 mm (length × width × thickness) for tensile loading, 145 mm × 25 mm × 4 mm for the compressive load, and 150 mm × 25 mm × 4 mm for the flexural load is considered for the present study, as per the ASTM-D3039, ASTM-D3410, and ASTM-D790 standards, respectively. Finite element analysis results showed good correlation with the analytical results. © 2024 by the authors.
A review on wrought magnesium alloys processed by equal channel angular pressing
(Inderscience Publishers, 2015) Muralidhar, M.; Narendranath, S.; Shivananda Nayaka, H.S.
Magnesium and its alloys with severe plastic deformation (SPD) techniques are more attractive as structural parts in many industrial applications because of their advantages. In this paper, the importance of wrought magnesium alloys with their applications to accomplish the essential development of components is reviewed. In addition, the different approaches of equal channel angular pressing (ECAP) process for refining the grain size to achieve the ultrafine grained material on the bulk metals are discussed. Recent developments in the ECAP process are outlined clearly with their importance to overcome many complexities. Various factors like processing temperature of a specimen, die geometry, ram speed, back pressure and processing routes influencing during ECAP process of wrought magnesium alloys at different conditions such as channel angle and corner or outer arc angle are discussed. Finally, the properties of ECAP processed wrought alloys are outlined for improving the microstructure in structural parts. © © 2015 Inderscience Enterprises Ltd.
Effect of Secondary Mg17Al12 Phase on AZ80 Alloy processed by Equal Channel Angular Pressing (ECAP)
(Springer Netherlands, 2018) Muralidhar, M.; Narendranath, S.
AZ80 alloy was subjected through Equal Channel Angular Pressing (ECAP) to refine the grains at three different temperatures 548 K, 573 K, and 623 K up to 4 passes for route Bc, where the specimen is rotated 90? counter-clockwise direction for each pass. In the present work, experiments have been continued with route Bc and the average grain size was obtained of 7 ?m, 9.5 ?m and 11.2 ?m for the temperatures of 548 K, 573 K, and 623 K respectively after 4 ECAP passes. The average grain size of the procured AZ80 alloy was found to be 44.5 ?m. Mechanical properties of AZ80 alloy have been improved to the corresponding various processing temperatures. X-ray diffraction studies have been done on a fourth ECAP processed specimen and compared with a zero pass specimen to know the phase transformation at different processing temperatures. Fracture behavior of each of the three materials was studied and it revealed brittle fracture by increasing the number of ECAP passes. © 2015, Springer Science+Business Media Dordrecht.
Exploring the Potential of Copper Slag and Quartz as Fine Aggregate Replacements in Concrete: A Comprehensive Study
(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Yadav, A.; Jayappa, S.M.; Mahadevaiah, R.R.; Gowda, S.; Jitesh, N.; Pasmanabh, J.; Anand, V.; Muralidhar, M.
In the realm of civil construction, river sand is an essential ingredient that cannot be overlooked. With the ever-increasing surge in construction activities, the demand for river sand has surged in tandem, resulting in its escalating scarcity, and subsequently, its price surge across the entire nation. This study delves into the utilization of copper slag as a viable alternative in the production of cement mortars, particularly as a partial replacement for fine aggregates. Experiments were conducted on concrete cubes and cylinders to determine the compressive strength and split tensile strength, respectively. Five cubes and cylinders were tested after 7, 14, and 21 days of curing. The extensive characterization of copper slag was conducted, encompassing its chemical composition, mineralogical attributes, and size distribution. The findings highlight that mortars containing copper slag exhibit superior compression resistance compared to the river sand-based mortars. Specifically, the 50% replacement of river sand with a blend of copper slag and quartz demonstrates the highest strength, surpassing the other compositions. Notably, the partial substitution of sand with copper slag outperforms both quartz and sand individually, with the optimal strength achieved at a 50% replacement rate. Copper slag, with its pozzolanic properties, showed a greater strength-enhancing potential, while quartz also exhibited positive effects. These findings are promising for optimizing concrete mix designs, reducing the environmental impacts caused by industrial by-products, and exploring natural alternatives. © 2024 by the authors. Licensee MDPI, Basel, Switzerland.
Finite Element Study on Coconut Inflorescence Stem Fiber Composite Panels Subjected to Static Loading
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Muralidhar, M.; Yadav, A.; Prasannakumar, S.; Mahadevaiah, R.R.; Hiremath, P.
Natural fiber-reinforced composites (NFCs) are alternatives to synthetic fiber-reinforced composites, since they are abundant in nature, inexpensive, lightweight, and have a high strength-to-weight ratio. Natural fibers encompass a diverse composition, including lignin, hemicellulose, wax, and cellulose. Natural fibers are environmentally friendly, biodegradable, renewable, reusable, and sustainable. In bio-composites, natural fibers such as jute, banana, hemp, coir, kenaf, areca nut, and coconut inflorescence stem fibers, are blended with resin. Natural fiber-reinforced bio-composites have various applications in the construction industry, automobile industry, aerospace industry, sports equipment and gadgets, textile industry, and hotel industry. Fibers from natural sources are also used as reinforcements in composites, such as roofing sheets, bricks, door panels, furniture panels, and panels for interior decoration. The mechanical properties of natural fiber-reinforced composites are profoundly influenced by the bonding between the fibers and the matrix. This study involves the testing of compact tension (CT) specimens under mode I fracture conditions and employs three-dimensional finite element analysis (FEA) using ANSYS software to enhance our understanding of the material’s fracture behavior. Finite element analysis was performed on coconut inflorescence stem fiber-reinforced composite (CIFRC) panels with preformed cracks. Numerical simulation was carried out using ANSYS software. Properties such as crack growth initiation, stress-intensity factor, and stresses along the length of a CIFRC panel were examined using finite element analysis (FEA). ASTM D-5045 standards were followed for the specimen size and the ASTM E399 standard was followed for the finite element pre-cracking. The simulation results were found to be in good agreement with the analytical results. © 2024 by the authors. Licensee MDPI, Basel, Switzerland.
Influence of Route-R on wrought magnesium AZ61 alloy mechanical properties through equal channel angular pressing
(National Engg. Reaserch Center for Magnesium Alloys zhangdingfei@cqu.edu.cn, 2014) Muralidhar, M.; Narendranath, S.
A new fundamental route entitled 'Route-R' is introduced to refine the grains in the material through Equal Channel Angular Pressing (ECAP) process. In route R, specimen is inverted to the original position in each ECAP pass. In the present work, AZ61 alloy is processed using ECAP process for three different fundamental routes mainly route A, route Bc, and route R. ECAP experiment is carried out on AZ61 alloy at lower temperature of 483 K up to two passes. Microstructural characterization is evaluated on unECAPed and ECAPed specimens for three routes. Average grain size of the alloy is to be reduced from 66 ?m to 16 ?m, 14.1 ?m and 10 ?m for route A routes Bc, and route R respectively. Vickers microhardness of the alloy is found to be 60 HV for as received material. This microhardness of the alloy is increased to 71 HV, 72 HV, and 74 HV for route A, route Bc, and route R respectively. Mechanical properties of the AZ61 alloy are observed to be route R is providing maximum YS, UTS, and percentage elongation than other route A and route Bc. Tensile fracture topography of the specimen is analyzed using three different routes for two passes. © 2014 National Engineering Research Center for Magnesium Alloys of China, Chongqing University.
Microstructure evolution in AZ61 alloy processed by equal channel angular pressing
(Hindawi Publishing Corporation 410 Park Avenue, 15th Floor, 287 pmb New York NY 10022, 2016) Muralidhar, M.; Narendranath, S.; Mashamba, M.
Magnesium and its alloys are finding increasing use in aerospace, automobile, nuclear, electrical, and structural engineering applications because of their high strength-to-weight ratio when compared to aluminum, titanium, and steel. In this work, AZ61 wrought magnesium alloy was processed using equal channel angular pressing at three different temperatures of 483, 523, and 573 K using up to four equal channel angular pressing passes. A microstructural study was conducted by measuring the average grain size after each pass, for the three different processing temperatures. The mechanical properties of the processed samples were noted to improve due to the reduction in the grain size after each equal channel angular pressing pass. After four equal channel angular pressing passes, the average grain size of the AZ61 samples was found to be reduced to 85%, 81%, and 70% for the pressing temperatures of 483, 523, and 573 K, respectively. The tensile strength of the AZ61 alloy increased with increase in the number of equal channel angular pressing passes for each of the temperatures when compared to as-received alloy. For instance, for the processing temperatures of 483, 523, and 573 K, the tensile strength increased by 24%, 10%, and 12%, respectively, at four equal channel angular pressing passes. Also, the percentage elongation of the alloy was increased with increase in processing temperatures. Moreover, fracture topographies of the tensile surfaces are illustrated through scanning electron microcopy and reveal ductile fracture than as-received alloy for four passes at each equal channel angular pressing processing temperature. © The Author(s) 2016.