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The Effect of Blanking Shear Angle on the Shearing Forces of Blanked Carbon Steel Sheets

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The Effect of Blanking Shear Angle on the Shearing Forces of Blanked Carbon Steel Sheets International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 11, November2018, pp. 1120–1128, Article ID: IJMET_09_11_115 Available online at http://iaeme.com/Home/issue/IJMET?Volume=9&Issue=11 ISSN Print: 0976-6340andISSN Online: 0976-6359 © IAEME Publication Scopus Indexed THE EFFECT OF BLANKING SHEAR ANGLE ON THE SHEARING FORCES OF BLANKED CARBON STEEL SHEETS Ali Abbar Khleif and Ahmad Saad Jasim Department of Production Engineering and Metallurgy University of Technology, Baghdad. Iraq. ABSTRACT In this study, numerical analysis has been conducted to investigate effects of shear angle on shearforcefor a low carbon steel sheet (AISI 1008). Five model shave been used in the blanking tests; one conventional flat end punchand four different bevels sheared rooftop punches of (0 °, 5 °, 10 °, 15 °,and 20°), which comparator of top punches. For the selected finite elements method, three-dimensional models were created. A finite element technique (ANSYS Workbench 15)was used for simulating the blanking process. The results showed that the blanking forces could be reduced radically with ideal bevel punch geometry. By using 10° shear angle at the punch end, the cutting force wasdecreased up to (90.5%) compared to the ones of the traditional flat end tool. Keywords: FEA, A sys, sheet metal, blanking, shearing force, and a punch shear angle. Cite this Article: Ali Abbar Khleif and Ahmad Saad Jasim, The Effect Of Blanking Shear Angle On The Shearing Forces Of Blanked Carbon Steel Sheets, International Journal of Mechanical Engineering and Technology, 9(11), 2018, pp. 1120–1128. http://iaeme.com/Home/issue/IJMET?Volume=9&Issue=11 1. INTRODUCTION The sheet metal working operations are extensively used in nearly all industries like defense, automotive, mechanical and medicinal manufacturing. The main benefit for using metal working operation is to advance production rate and to decrease the price per part [1].One of the sheet metal working processes is blanking process; the blanking operation used in the industrial manufacturing establishes the first step of several forming processes. Blanking is the operation of shearing or cutting, from sheet-metal stock, a piece of metal of predetermined contour to attend it for subsequent processes [2].A significant challenge confronted when using blanking to machine sheet metal is the treatment of the shearing force in demand for thick stock and high strength. Increased shearing forces lead to the demand of higher accomplishment predictable from the conclusion in increased wear on the die and punch tool and pressing machine. One of the methods used to decrease the force wanted is the increase of a punch shear angle [3]. http://iaeme.com/Home/journal/IJMET 1120 [email protected] Ali Abbar Khleif and Ahmad Saad Jasim There are many studies in the literature that deal with the scope of blanking process.One of the successful attempts was made by[4], gave the expansion of a pattern to portend the form of the cut side. The model studied the influence of possible parameters affecting the blanking operation and their interactions. This assisted in selecting the operation importantparameters for two conformable units fabricated from two various substances blanked with a plausible quality on the same mold. Finite Element Method and Design of Experiment process were utilizedso as to perform the objectives of purposed model. A collection for both systems was suggested to cause a decrease in the essential experimental price and potential in addendumfor obtaining a higher plane of realization. It can be expressed that the (FEM) fastened with Design of Experiments method supply a significant contribution across the optimization of sheet metal blanking operation. Mackensenet al. [5] offered potentials for decreasing these forces. Experimental studieshave beenconductedusing a novel tool concept that couldassociateessential blanking forces to punch stroke in three dimensions and indirect force path. The results from three various AHSS materials have been presented indicating the differencesindecisive blanking variablesfor example clearance, shearing angle and sheet positioning angle. Behrens et al.[6] invest gated concentrates effects on blanking of thin steel sheets of Dogal1000DP +Z100MBO. Experimental and numerical studies on the effect of punch speed and clearance on the cutting force and the sheared edge geometry have been performed. Tensile and compressive tests at raised temperature were selected for defining the flow and fracture attitude of Dogal1000DP +Z100MBO at various stresses situations. It was displayed that flow curve limited by stack compressive test guides to finer result in force-displacement foretelling of a blanking operation compared by tensile test for determining flow curve. Stress established fracture criterions have been selected for defining damage behavior. Furthermore,the significant effect of fracture locus for negative stress on the geometric of the numerical prophesied sheared edge was presented. Numerical and experimental studies were performed by Wang and Wierzbicki, 2015 [7]on the plane-strain blanking operation in an try to know how the blanking operation acts edge fracture. Blanking experiments on a DP780 steel sheet have been conducted for the Digital Image Correlation (DIC) deformation measurement on a particular fixture using an in-situ microscope. The DIC method supplies a specified deformation field of the sample that was not described in any another publication before. Discontinuous examinations havebeen performedfor investigating the crack creation and spread through the blanking process, although Scanning Electron Microscope (SEM) has been usedfor inspecting the surface quality of blank in addition to the edge profile after the experiment. After the experiment study, a specified (FEM) Model in the critical zone with mesh dimension of 0.01mm for the numerical study was establishing. With matter parameters standardized from the in-plane investigations in addition to precise edge conditions calculated in real examinations, the Finite Element model precisely estimated the blanking operation quantitatively. The present investigation provided quantitative amounts of the parameters of interest through the blanking examination, for example, the local strain inclination history and the universal load-displacement responses. The geometrical characteristics forblanked edge, the extent of the burnished zone and fracture region have been all precisely calculated using current simulation. Through the study of the blanking mechanism (Zhank et al., 2016) [8], it is found that the blanking clearance and the convex die cutting edge radius seriously influence the quality of fracture surface, the wear depth of the punch and the load of the punch. After establishing the appropriate models, finite element analysis software Deform-3D has been implemented for simulating the above forming parameters. The curves between the forming parameters and the quality of fracture surface, the wear depth of the punch and the load of the punch were obtained, optimizing the optimal forming parameters. On these bases, presents five solutions to improve the punch structure. It was found that the comprehensive performance of internal spherical punch is best by comparing the quality of fracture surface, the wear depth of the punch and the http://iaeme.com/Home/journal/IJMET 1121 [email protected] The effect of Blanking Shear Angle on the Shearing Forces of Blanked Carbon Steel Sheets max principal stress of the punch. Kumari and Tagore, 2016[9] performed analytical investigations to optimize the factor sheet clearance,and material type for a sheet metal blanking die. Different values for each sheet clearance factor were taken and optimized on the basis of stresses and deformations produced. 3D models of the blanking die and total assembly were done in Pro/Engineer. The forces applied on the blanking die were calculated theoretically. Structural analysis was performed for differentblank materials SS and Aluminum. The analysishas been donebyusing ANSYS software. Patil and Kadlag, 2016[10] studied the influence of quality parameters affecting the blanking operation & their interaction. This helps to select the process leading parameters for similar work piece manufactured from two different materials blanked with suitable quality. Finite element method & taguchi method approaches are useful in order to achieve the required objective of the project. The combination of these two techniques provided a good solution for the optimization of sheet metal blanking process. The study helped to estimate the effect of sheet material thickness, tool clearance, and sheet material. It is useful that before manufacturing blanking die, to do Finite element analysis to know the parameters effect & go for feasible& result oriented design. The result from Taguchi method & finite element method is then validated with physically design blanking die. Engin and Eyercioglu, 2017[11]conducted FEM and experimental investigations for observingclearance effects on punch load, cutting energy and surface zone distributions. AISI 304 stainless steel with 2 mm thickness was blankedutlizing a 300 KN hydraulic pressurewith five virous clearance values (1%, 3%, 5%, 10% and 20% of thickness) for experiment studies. Deform 2D was used for modeling of the process. The results showed that if the purpose is to achieve good surface quality, less than 5% clearance should be used. If punch loads are the main concern, more than
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