Multiresponse optimization of cryogenic drilling on Ti-6Al-4V alloy using topsis method

L. Shakeel Ahmed,M. Pradeep Kumar 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Multiresponse optimization of process parameters in drilling is focused in this article using the TOPSIS technique to obtain minimum cutting temperature (T), thrust force (F t ), torque (M t ) and surface roughness (R a ), Circularity (Cir), Cylindricity (Cyl). The experiments were performed on Titanium alloy Ti-6Al-4V in different cooling environments: Wet cooling and cryogenic cooling conditions. Liquid nitrogen (LN 2 ) as a coolant is used in cryogenic machining. The control factors selected were machining environments, cutting speed (V c ) and feed rate (f). Eighteen experiments were conducted in wet and cryogenic LN 2 conditions based on L 18 orthogonal array, respectively. The optimization results indicate drilling at V c = 40 m/min and f = 0.02 mm/rev which is of the lowest value in cryogenic LN 2condition. A better performance is achieved too. The optimum multiresponses show that TOPSIS method is the most effective performance in the drilling process.

AUGMENTED INVERSE GRAPHS WITH RESPECT TO A GROUP

M. LAKSHMI KAMESWARI,N. NAGA MARUTHI KUMARI,T.V. PRADEEP KUMAR The Korean Society for Computational and Applied M 2023 Journal of applied mathematics & informatics Vol.41 No.2

In this paper, the Augmented graph Es(τ) of the inverse graph Gs(τ) of a cyclic group (τ,◦) was studied. The Augmented inverse graph was constructed by applying the method of Mycielski's construction. The dimension of Augmented inverse graph and different properties of the graph were investigated. Later the chromatic number of Augmented inverse graph was discussed and the relation between the maximum degree of the graph and the chromatic number was established. In the Mycielski's construction, the properties of the key node 'u' in Es (τ) were established based on cardinality of the cyclic group (τ,◦) and also proved that the Augmented inverse graph Es(τ) was a triangle free graph.

Some Properties of q-Distance Energy

M. R. Rajesh Kanna,R. Pradeep Kumar,Soner Nandappa D,Ismail Naci CANGUL 장전수학회 2020 Advanced Studies in Contemporary Mathematics Vol.30 No.2

Graphs are nowadays frequently used in modelling. Especially the sub area of graph theory called the molecular graph theory deals with physicochemical proper- ties of chemical substances by means of mathematical methods. Three main methods to study graphs mathematically are to make use of the vertex degrees, distances and matrices. The classical graph energy was dened 1978 by I. Gutman and has a large number of applications in chemistry and physics. In this paper, a recently dened new type of energy called q-distance energy by means of distances and matrices is studied and q-distance energies of star graph, complete graph, crown graph, cocktail party graph, complete bipartite graph, windmill graph are computed.

Influence of an upstream transonic axial compressor stage on the performance of inter-stage duct

Lakshya Kumar,Dilipkumar B. Alone,A. M. Pradeep 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.5

In this investigation, an inter-stage duct (ISD) design is carried out for three lengths based on the guidelines available in the open literature. The performance of the design is analyzed considering a stand-alone ISD with uniform inlet velocity and the flow coming from an upstream transonic compressor stage (TCS). The computational analysis is carried out for a 20° sector geometry. Three turbulence models, namely, SST, k-ε, and Reynolds stress, are compared for loss predictions. The flow behavior of the individual ducts is observed to be free from separation and is uniform at the exit. However, the duct performance is severely affected due to the presence of the upstream TCS. This investigation sheds light on the importance of considering upstream conditions for ISD design.

Experimental investigation of the process parameters in cryogenic cooled electrode in EDM

Vinoth Kumar. S,Pradeep Kumar. M 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.9

Investigations were conducted on the machining of AISI D2 tool steel via Conventional electrical discharge machining (CEDM) andCryogenic cooled electrode in electrical discharge machining (CCEDM). Machining parameters, including discharge current, pulse ontime, and gap voltage, were varied to investigate their effects on machining performance such as on Electrode wear ratio (EWR), surfaceroughness (Ra), microstructure, surface morphology, and elemental composition. Experimental results showed that EWR was reduced by20% in CCEDM compared with in CEDM. Moreover, the Ra in CCEDM decreased by approximately 19% compared with that inCEDM. The results also indicated that the surface morphology of the workpiece machined via CCEDM was better than that of the workpiecemachined via CEDM. Lastly, the damaged layer and microcracks were less in the workpiece machined via CCEDM than those inthe workpiece machined via CEDM.

Multi-objective equilibrium optimizer: framework and development for solving multi-objective optimization problems

Premkumar M,Jangir Pradeep,Sowmya R,Alhelou Hassan Haes,Mirjalili Seyedali,Kumar B Santhosh 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.1

This paper proposes a new Multi-Objective Equilibrium Optimizer (MOEO) to handle complex optimization problems, including real-world engineering design optimization problems. The Equilibrium Optimizer (EO) is a recently reported physics-based metaheuristic algorithm, and it has been inspired by the models used to predict equilibrium state and dynamic state. A similar procedure is utilized in MOEO by combining models in a different target search space. The crowding distance mechanism is employed in the MOEO algorithm to balance exploitation and exploration phases as the search progresses. In addition, a non-dominated sorting strategy is also merged with the MOEO algorithm to preserve the population diversity and it has been considered as a crucial problem in multi-objective metaheuristic algorithms. An archive with an update function is used to uphold and improve the coverage of Pareto with optimal solutions. The performance of MOEO is validated for 33 contextual problems with 6 constrained, 12 unconstrained, and 15 practical constrained engineering design problems, including non-linear problems. The result obtained by the proposed MOEO algorithm is compared with other state-of-the-art multi-objective optimization algorithms. The quantitative and qualitative results indicate that the proposed MOEO provides more competitive outcomes than the different algorithms. From the results obtained for all 33 benchmark optimization problems, the efficiency, robustness, and exploration ability to solve multi-objective problems of the MOEO algorithm are well defined and clarified. The paper is further supported with extra online service and guideline at https://premkumarmanoharan.wixsite.com/mysite.

Optimization of cryogenic cooled EDM process parameters using grey relational analysis

Vinoth Kumar. S,Pradeep Kumar. M 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

This paper presents an experimental investigation on cryogenic cooling of liquid nitrogen (LN2) copper electrode in the electrical dischargemachining (EDM) process. The optimization of the EDM process parameters, such as the electrode environment (conventionalelectrode and cryogenically cooled electrode in EDM), discharge current, pulse on time, gap voltage on material removal rate, electrodewear, and surface roughness on machining of AlSiCp metal matrix composite using multiple performance characteristics on grey relationalanalysis was investigated. The L18 orthogonal array was utilized to examine the process parameters, and the optimal levels of theprocess parameters were identified through grey relational analysis. Experimental data were analyzed through analysis of variance. Scanningelectron microscopy analysis was conducted to study the characteristics of the machined surface.

End milling of DIN 1.2714 die steel with cryogenic CO2 cooling

Jebaraj M.,Pradeep Kumar M. 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.5

Currently, cryogenic coolants are used instead of normal cutting fluid in transferring excessive heat from the cutting region and retaining cutting tool edge sharpness during the machining process, and to eliminate the hazardous effects of cutting fluids. In this investigation, end milling experiments with various cooling approaches were performed on DIN 1.2714 die steel using titanium aluminum nitratecoated carbide tool inserts under dry, conventional coolant, and cryogenic CO 2 environments. The end milling performance under CO 2environment has been compared with those under dry and wet conditions regarding cutting temperature (T c ), feed force (F x ), normal force (F y ), axial force (F z ), surface roughness (R a ), tool wear, surface and chip morphology, and residual stress. The consequences of these machining environments were evaluated. Using cryogenic CO 2 cooling technique reduced the T c values by approximately 50.49 % and 64.42 % compared with those of wet and dry conditions, respectively. Similarly, CO 2 cooling diminished the cutting forces, namely, F x , F y and F z . As a result, R a values reduced by approximately 59.81 % and 67.15 % compared with those of wet and dry conditions, respectively. Cryogenic CO 2 caused a significant reduction in surface damage and abrasion wear in the machined surfaces and cutting inserts, respectively. No substantial changes in residual stress were observed at the cut surfaces.

Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

N. Pragadish,M. Pradeep Kumar 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of thedebris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDMprocesses and the performance of both processes is compared. Experiments were designed using Taguchi’s L27 orthogonal array. Dischargecurrent (I), gap voltage (V), pulse on time (TON), gas pressure (P) and tool rotational speed (N) were chosen as the various inputparameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elementalcomposition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machinedunder dry EDM process.

Grinding titanium Ti-6Al-4V alloy with electroplated cubic boron nitride wheel under cryogenic cooling

Elanchezhian J.,Pradeep Kumar. M,Manimaran G. 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

A grinding experiment was conducted with Ti-6Al-4V alloy in a wet and cryogenic coolant environment. An electroplated cubic boronnitride grinding wheel was used for this experiment. The input process parameters that were considered were depth of cut and nozzleinclination angle. The output response parameters that were considered were tangential forces, normal forces, grinding zone temperature,specific energy, and surface roughness (Ra). Experimental results indicate an 8% to 27% reduction in tangential force and 3% to 12%reduction in normal force when liquid nitrogen was used as coolant. Ra is reduced by a maximum of 38% over wet grinding, and grindingzone temperature is reduced by up to 55%. Surface modification and chip morphology were analyzed. Experimental results indicated thatthe nozzle angle at 45o has a significant effect on the grinding process.