Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
3 results
Search Results
Item Delamination analysis in drilling process of glass fiber reinforced plastic (GFRP) composite materials(2007) Mohan, N.S.; Kulkarni, S.M.; Ramachandra, A.Machining processes are generally used to cut; drill, or contour composite laminates for building products. In fact, drilling is one of the most commonly used manufacturing processes to install fasteners for assembly of laminate composites. The material anisotropy resulting from fiber reinforcement heavily influences the machinability during machining. Machining of fiber reinforced plastic (FRP) components is often needed in spite of the fact that most FRP structures can be made to near-net shape and drilling is the most frequently employed secondary machining process for fiber reinforced materials. Therefore, the precise machining needs to perform to ensure dimensional stability and to obtain a better productivity of the component. The drilling parameters and specimen parameters evaluated were speed, feed rate, drill size and specimen thickness. A series of experiments were conducted using TRIAC VMC CNC machining center to machine the composite laminate specimens at various cutting parameters and material parameters. The measured results of delamination at the entry and exit side of the specimen were measured and analyzed using commercial statistical software MINITAB14. The experimental results indicated that the specimen thickness, feed rate and cutting speed are reckoned to be the most significant factors contributing to the delamination. A signal-to-noise ratio is employed to analyze the influence of various parameters on peel up and push down delamination factor in drilling of glass fibre reinforced plastic (GFRP) composite laminates. The main objective of this study is to determine factors and combination of factors that influence the delamination using Taguchi and response surface methodology and to achieve the optimization machining conditions that would result in minimum delamination. From the analysis it is evident that among the all significant parameters, specimen thickness and cutting speed have significant influence on peel up delamination and the specimen thickness and feed have more significant influence on push down delamination. Confirmation experiments were conducted to verify the predicted optimal parameters with the experimental results, good agreement between the predicted and experimental results obtained to be of the order of 99%. © 2007 Elsevier B.V. All rights reserved.Item Predictive analysis of peel up delamination in glass fibre reinforced polyester composite drilling(Transstellar Journal Publications and Research Consultancy Private Limited (TJPRC) editor@tjprc.org, 2019) Bhat, R.; Mohan, N.; Kulkarni, S.M.; Sharma, S.Composites are the engineering materials, comprising two constituents: reinforcing and the matrix or binder material. the composite machining, particularly, drilling is a complex process in comparison to the machining of traditionally employed engineering structural materials. Delamination is the most prevalent integrity issue in composite drilling. In the present work, the independent variables are categorized as continuous and categorical variables. Speed and feed are chosen as the continuous variables, whereas, the drill tool diameter and material thickness are considered as categorical variables. The peel up delamination is chosen as the response. The central composite design form of RSM is employed to develop the experimental design and develop the response regression model. The developed model is then validated using an additional set of small number of experiments and the degree of affirmation is determined. The standard error obtained analytically is 5.91%. The experimental mean standard error for the randomly conducted validating experiment obtained is 4.23%. The validation shows a high degree of agreement (99.75%) between the theoretical and analytical values. © TJPRC Pvt. Ltd.