An Investigation into Orthogonal and Oblique Cutting Processes


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An Investigation into Orthogonal and Oblique Cutting Processes
MAHMOOD, Zahid Available from Sheffield Hallam University Research Archive (SHURA) at: http://shura.shu.ac.uk/25510/
This document is the author deposited version. You are advised to consult the publisher's version if you wish to cite from it. Published version MAHMOOD, Zahid (2018). An Investigation into Orthogonal and Oblique Cutting Processes. Masters, Sheffield Hallam University. Copyright and re-use policy See http://shura.shu.ac.uk/information.html
Sheffield Hallam University Research Archive http://shura.shu.ac.uk

“An Investigation into Orthogonal and Oblique Cutting Processes”
ZAHID MAHMOOD A thesis submitted in partial fulfilment of the requirements of
Sheffield Hallam University for the degree of Master of Philosophy
October 2018 1

Acknowledgement I would like to thank my project supervisors for their inestimable support, assistance, guidance, encouragement and recommendations without which the present study would have not been completed successfully. I am also thankful to the administrative and academic staff of the Sheffield Hallam University for their assistance to provide me research and databases facilities. I also pay my thanks to those who have already researched on cutting process. I am also thankful to other academic staff in building up my knowledge base and think tank for conducting current study research, analysis and dissertation write up. I am also thankful to my friends and family members whom names I did not cite here for their support, encouragement and best wishes for completion of my present study.
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Preface This report has been prepared to describe research work on understanding of metal sheet cutting (punching and Shearing) carried out in the faculty of Science, Technology and Arts at Sheffield Hallam University in 2018-2019. The report is submitted in accordance with the requirement for the award of the degree of M.Phil under the auspices of the Sheffield Hallam University.
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Abstract The cutting process may be divided into two major types. The one type is called as straight angle cutting, where blade is in continuous contact with metal sheet from one side of edge to another side of the edge at the beginning of the cutting process. The another type is known as shearing, where the blade edge is oblique and progressively proceed from one edge of metal sheet to other end of metal sheet during cutting process. The present study has investigated straight angle cutting and shearing processes by using virtual environment of software ANSYS 19-R. An explicit dynamic FEM analysis was used in various simulations of punching and shearing investigations. The current study has two four parts. In first part, impact of attack angle variation on stress generated on tool and work piece has been investigated. Both punching and shearing processes have been simulated in software environment to understand and differentiate both cutting processes. In second part, straight angle tool was used to create straight angle cutting environment. Various cutting parameters including tool, metal sheet and cutting process parameters have been investigated for straight angle cutting. In third part, oblique angle tool was used to create shearing environment. Various cutting parameters including tool, metal sheet and cutting process parameters have been investigated for shearing. In fourth part, straight angle cutting and oblique angle cutting process has been compared to find out impact of various parameters on straight angle cutting and shearing and how these may be differentiated. The cutting process is complex and depends upon tool, metal sheet and cutting process parameters. Tool parameters investigated in present study include tool edge angle, tool attack angle, tool material and tool thickness. The metal sheet parameters affecting cutting process have been investigated in the present study and include metal sheet material and metal sheet thickness. Cutting process parameters investigated in present study include cutting process speed and friction between metal sheet and tool. Both punching and shear cutting simulations has been designed in present study by considering guillotining machine.
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Table of contents 1. Chapter 1; Introduction ....................................................................................................14
1.1 Aim & Objectives......................................................................................................18 1.2 Background ...............................................................................................................19 1.3 Contribution to knowledge........................................................................................20 2. Chapter 2; Literature review ............................................................................................21 2.1 What is cutting process .............................................................................................21 2.2 Shearing versus straight angle cutting.......................................................................22 2.3 Significance of shearing ............................................................................................23 2.4 Shearing stress...........................................................................................................24 2.5 Parameters impacting Shearing process ....................................................................26 2.6 Surface finish in shearing process............................................................................32 3. Chapter 3; Methodology ..................................................................................................34 3.1 Experimental Design .................................................................................................36 3.2 Experimental CAD model.........................................................................................37 3.3 Simulation protocol ...................................................................................................37 3.4 Data collection and results ........................................................................................41 4. Chapter 4; Results ............................................................................................................45 4.1 Impact of attack angle variation on cutting process ..................................................45 4.2 Straight angle cutting ................................................................................................45 4.3 Shearing.....................................................................................................................49
4.3.1 Stress versus various metal sheet material.........................................................49 4.3.2 Stress versus various tool material.....................................................................49 4.3.3 Stress versus various friction values ..................................................................49 4.3.4 Stress versus various tool speed values .............................................................49 4.3.5 Stress versus Force applied................................................................................49 4.3.6 Stress versus metal sheet thickness & stress versus Tool thickness ..................50 4.4 Roughness Test .........................................................................................................50 5. Chapter 5; Discussion & Conclusion...............................................................................54 5.1 Discussion .................................................................................................................54 5.2 Conclusion.................................................................................................................61 5.3 Further research and study ........................................................................................62 6. Chapter 6; Bibliography...................................................................................................64 6.1 References .................................................................................................................64 6.2 Books.........................................................................................................................70 6.3 Websites ....................................................................................................................71 7. Chapter 7; Appendix-Shearing ........................................................................................72 7.1 Attack angle Investigations .......................................................................................72 7.1.1 Attack angle 45 ..................................................................................................72 7.2 Oblique angle – Investigations..................................................................................76 7.2.1 Tool Thickness versus stress..............................................................................76 7.2.2 Metal sheet Thickness versus stress...................................................................79 7.2.3 Friction versus stress – Investigations ...............................................................83 7.2.4 Velocity of the tool relative to the work piece – Investigations ........................91 7.2.5 Tool material versus Stress ................................................................................96
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7.2.6 Metal Sheet material versus Stress ..................................................................101 7.3 Straight Angle investigations ..................................................................................105
7.3.1 Tool Thickness versus stress – Investigations .................................................105 7.3.2 Metal sheet Thickness versus stress.................................................................108 7.3.3 Friction versus stress – Investigations .............................................................112 7.3.4 Velocity of the tool relative to the work piece – Investigations ......................122 7.3.5 Tool material versus Stress ..............................................................................127 7.3.6 Metal Sheet material versus Stress ..................................................................132 8. Appendix- Material properties.......................................................................................136 8.1 Material used in tool investigations ........................................................................136 8.1.1 Tool material steel (T1 tool steel)....................................................................136 8.1.2 Tool material steel ((H22 tool steel) ................................................................137 8.1.3 Tool material steel (W1 tool steel)...................................................................138 8.1.4 Tool material steel (W1 tool steel)...................................................................139 8.1.5 Tool material steel (D2 tool steel), versus stress ...........................................140 8.1.6 Tool material steel (H 13) ................................................................................141 8.2 Metal sheet materials used in simulations...............................................................142 8.2.1 Metal Sheet material (Aluminum Alloy high strength) ...................................142 8.2.2 Metal Sheet material (Aluminium AL2024 )...................................................143 8.2.3 Metal Sheet material (Aluminium 7039 With Young modulus ) ....................144 8.2.4 Metal Sheet material (Aluminium AL 1100-O ).............................................145 9. Appendix L: Roughness Test.........................................................................................146 10. Appendix 10; Straight angle versus Oblique cutting .....................................................147 11. Appendix; Experimental conditions ..............................................................................148 11.1 Tool edge angle variation versus stress...................................................................148 11.2 Straight angle study experimental conditions .........................................................149 11.2.1 Straight angle study experimental conditions (continued)...............................150 11.2.2 Straight angle study experimental conditions (continued)...............................151 11.3 Oblique angle study experimental conditions .........................................................152 11.3.1 Straight angle study experimental conditions (continued)...............................153 11.3.2 Straight angle study experimental conditions (continued)...............................154
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List of figures Figure 1; Guillotine machine with two blades.........................................................................16 Figure 2; gallstone machine with one oblique blade and metal sheet support on both sides ..17 Figure 3; Guillotine metal cutting (shearing)...........................................................................25 Figure 4; Guillotine machine with blade angle of 90 Degree(Straight angle cutting).............25 Figure 5; Shearing....................................................................................................................25 Figure 6; Shearing....................................................................................................................25 Figure 7; Cutting parameters ...................................................................................................28 Figure 8; Basic principle of roughness test..............................................................................33 Figure 9; Basic principle of roughness test..............................................................................33 Figure 10; Basic principle of roughness test............................................................................33 Figure 11; Present study Methodology ....................................................................................35 Figure 12; Tool Dimensions ....................................................................................................38 Figure 13: Metal sheet Dimensions .........................................................................................38 Figure 14; Tool Thickness 1.6mm, Work piece thickness 1.6 mm (90 Angle ) ......................38 Figure 15; Tool angle 30 in shearing investigations ................................................................38 Figure 16; Concept of shearing in present study .....................................................................39 Figure 17; Experimental model used in current study .............................................................40 Figure 18; Explicit dynamic analysis module(ANSYS)........................................................42 Figure 19; Material was selected .............................................................................................42 Figure 20; material was assigned to tool and sheet..................................................................42 Figure 21; Body interaction defined ........................................................................................42 Figure 22; Meshing designed and applied to tool and chip. ....................................................42 Figure 23; Analysis setting defined .........................................................................................42 Figure 24; Displacement ..........................................................................................................43 Figure 25;Displacement application ........................................................................................43 Figure 26; Relative speed.........................................................................................................43 Figure 27: Relative speed application......................................................................................43 Figure 28; Fixed support;.........................................................................................................43 Figure 29; Fixed support application .......................................................................................43 Figure 30; Defining analysis setting ........................................................................................44 Figure 31; defining output solution..........................................................................................44 Figure 32; Elastic strain ...........................................................................................................44 Figure 33; Attack angle variation versus stress .......................................................................46 Figure 34; Friction versus stress(Straight angle cutting) .........................................................47 Figure 35; relative speed versus stress(Straight angle cutting)................................................47 Figure 36; Tool thickness versus stress(Straight angle cutting) ..............................................47 Figure 37; Work piece thickness versus stress(Straight angle cutting) ...................................47 Figure 38; Sheet material versus stress(Straight angle cutting)...............................................48 Figure 39; force versus stress...................................................................................................48 Figure 40; Tool material versus stress(Straight angle cutting) ................................................48 Figure 41; Friction versus stress(Shearing) .............................................................................51 Figure 42; Tool thickness versus stress(Shearing)...................................................................51 Figure 43; Sheet thickness versus stress(Shearing) .................................................................51 Figure 44; Relative speed versus stress(Shearing)...................................................................51 Figure 45; Sheet material versus stress(Shearing) ...................................................................52 Figure 46; Force versus stress..................................................................................................52 Figure 47; Tool material versus stress(Shearing) ....................................................................52
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Figure 48; Roughness versus Force .........................................................................................53 Figure 49; Roughness versus metal sheet thickness ................................................................53 Figure 50; Friction versus stress (comparison) ........................................................................58 Figure 51; Tool thickness versus stress( comparison) .............................................................58 Figure 52; Sheet thickness versus stress (comparison)............................................................58 Figure 53; Relative speed versus stress (comparison) .............................................................58 Figure 54; Sheet material versus stress (comparison)..............................................................59 Figure 55; Tool material versus stress (comparison ................................................................59 Figure 56; Force versus stress..................................................................................................59 Figure 57; Elastic strain;Attack angle investigation ................................................................72 Figure 58; Plastic strain ...........................................................................................................73 Figure 59; Equivalent stress.....................................................................................................74 Figure 60; shear stress..............................................................................................................75 Figure 61;Deformation (oblique angle simulation) .................................................................76 Figure 62;Elastic strain ............................................................................................................76 Figure 63;Equuivalent Stress (tool thickness 1mm) ................................................................76 Figure 64;Shear stress ..............................................................................................................76 Figure 65:Deformation.............................................................................................................77 Figure 66;Strain .......................................................................................................................77 Figure 67; Stress ......................................................................................................................77 Figure 68; Shear stress ............................................................................................................77 Figure 69:Deformation.............................................................................................................78 Figure 70;Strain .......................................................................................................................78 Figure 71; Stress ......................................................................................................................78 Figure 72; Shear stress ............................................................................................................78 Figure 73;Deformation.............................................................................................................79 Figure 74;Elastic strain ............................................................................................................79 Figure 75; Equivalent stress (sheet thickness 1mm)................................................................79 Figure 76;Shear stress ..............................................................................................................79 Figure 77;Deformation.............................................................................................................80 Figure 78;Elastic strain ............................................................................................................80 Figure 79; Stress ......................................................................................................................80 Figure 80;Shear stress ..............................................................................................................80 Figure 81;Deformation.............................................................................................................81 Figure 82;Elastic strain ............................................................................................................81 Figure 83; Stress ......................................................................................................................81 Figure 84;Shear stress ..............................................................................................................81 Figure 85;Deformation.............................................................................................................82 Figure 86;Elastic strain ............................................................................................................82 Figure 87; Stress ......................................................................................................................82 Figure 88;Shear stress ..............................................................................................................82 Figure 89; Deformation............................................................................................................83 Figure 90; Elastic strain ...........................................................................................................83 Figure 91; Equivalent stress (F coefficient 0.2).......................................................................83 Figure 92; shear stress..............................................................................................................83 Figure 93; Deformation............................................................................................................84 Figure 94; Elastic strain ...........................................................................................................84 Figure 95; Equivalent stress.....................................................................................................84 Figure 96;Shear stress ..............................................................................................................84 Figure 97;Deformation.............................................................................................................85
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Figure 98; Elastic strain ...........................................................................................................85 Figure 99; Equivalent stress.....................................................................................................85 Figure 100; Shear stress ...........................................................................................................85 Figure 101; Deformation..........................................................................................................86 Figure 102; Elastic strain .........................................................................................................86 Figure 103; Equivalent stress...................................................................................................86 Figure 104; Shear stress ...........................................................................................................86 Figure 105; Deformation..........................................................................................................87 Figure 106;Elastic strain ..........................................................................................................87 Figure 107; Equivalent stress...................................................................................................87 Figure 108; Shear stress ...........................................................................................................87 Figure 109;Deformation...........................................................................................................88 Figure 110; Elastic strain .........................................................................................................88 Figure 111;Equivalent stress....................................................................................................88 Figure 112; Shear stress ...........................................................................................................88 Figure 113; Deformation..........................................................................................................89 Figure 114; Elastic strain .........................................................................................................89 Figure 115; Equivalent stress...................................................................................................89 Figure 116; Shear stress ...........................................................................................................89 Figure 117; Deformation..........................................................................................................90 Figure 118; Elastic strain .........................................................................................................90 Figure 119; Equivalent stress...................................................................................................90 Figure 120; Shear stress ...........................................................................................................90 Figure 121; Deformation..........................................................................................................91 Figure 122;Elastic strain ..........................................................................................................91 Figure 123 Equivalent stress (speed 10m/sec).........................................................................91 Figure 124; Shear stress ...........................................................................................................91 Figure 125; Deformation..........................................................................................................92 Figure 126; Elastic strain .........................................................................................................92 Figure 127;Equivalent stress....................................................................................................92 Figure 128; Shear stress ...........................................................................................................92 Figure 129; Deformation..........................................................................................................93 Figure 130; Elastic strain .........................................................................................................93 Figure 131; Equivalent stress...................................................................................................93 Figure 132; Shear stress ...........................................................................................................93 Figure 133; Deformation..........................................................................................................94 Figure 134; Elastic strain .........................................................................................................94 Figure 135; Equivalent stress...................................................................................................94 Figure 136; Shear stress ...........................................................................................................94 Figure 137; Deformation..........................................................................................................95 Figure 138; Elastic strain .........................................................................................................95 Figure 139; Equivalent stress...................................................................................................95 Figure 140; Shear stress ...........................................................................................................95 Figure 141; Deformation..........................................................................................................96 Figure 142; Elastic strain .........................................................................................................96 Figure 143; Equivalent stress (Tool material T1) ....................................................................96 Figure 144; Shear stress ...........................................................................................................96 Figure 145; Deformation..........................................................................................................97 Figure 146; Elastic strain .........................................................................................................97 Figure 147; Equivalent stress...................................................................................................97
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An Investigation into Orthogonal and Oblique Cutting Processes