STUDY ON THE DEVELOPMENT OF AXIAL STRESSES IN WOUND ROLLS By ANGELA DE’ON WELCH Bachelor of Science in Mechanical Engineering Oklahoma State University Stillwater, OK 2006 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE December, 2006 STUDY ON THE DEVELOPMENT OF AXIAL STRESSES IN WOUND ROLLS Thesis Approved: J. K. Good Thesis Adviser D. E. Fisher C. E. Price A. Gordon Emslie Dean of the Graduate College ii TABLE OF CONTENTS Chapter Page I. INTRODUCTION TO STRESSES IN WOUND ROLLS.........................................1 II. BACKGROUND INFORMATION..........................................................................6 One-Dimensional Winding Models.........................................................................7 Two-Dimensional Winding Models......................................................................13 III. DISCUSSION ON TWO-DIMENSIONAL WINDING MODEL AND APPLICATION TO THE POLYESTER WEB TO BE TESTED…………………...16 Material Properties.................................................................................................18 Model Outputs.......................................................................................................25 IV.EXPERIMENTAL PROCEDURE.........................................................................35 V. EXPERIMENTAL RESULTS................................................................................46 VI.COMPARISON OF MODEL AND EXPERIMENTAL RESULTS.....................56 VII.CONCLUSIONS...................................................................................................77 Conclusions............................................................................................................78 Future Work...........................................................................................................81 REFERENCES............................................................................................................83 APPENDIX..................................................................................................................86 iii LIST OF TABLES Table Page Table 1: Material Properties.........................................................................................19 Table 2: Statistical Results for MD Strains in 6 inch Wide PET.................................48 Table 3: Statistical Results for CMD Strains in 6 inch Wide PET..............................49 Table 4: Statistical Results for MD Strains in 24 inch Wide PET...............................52 Table 5: Statistical Results for CMD Strains in 24 inch Wide PET............................53 iv LIST OF FIGURES Figure Page Figure 1: Circumferential Corrugations.........................................................................2 Figure 2: Experimental Area of High Speed Web Line.................................................5 Figure 3: Changing Radial Stress with Changing ν and Constant ν and ν ...........20 θz θr zr Figure 4: Changing Tangential Stress with Changing ν and Constant ν and ν ....21 θz θr zr Figure 5: Changing Axial Stress with Changing ν and Constant ν and ν .............22 θz θr zr Figure 6: Radial Stress Through 6 inch Web...............................................................26 Figure 7: Tangential Stress Through 6 inch Web........................................................27 Figure 8: Axial Stress Through 6 inch Web................................................................28 Figure 9: Radial Stress Through 24 inch Web.............................................................29 Figure 10: Tangential Stress Through 24 inch Web....................................................30 Figure 11: Axial Stress Through 24 inch Web............................................................31 Figure 12: Radial Stress in Wound Roll of PET..........................................................32 Figure 13: Tangential Stress in Wound Roll of PET...................................................33 Figure 14: Axial Stress in Wound Roll of PET...........................................................34 Figure 15: Rosette Strain Gage....................................................................................35 Figure 16: Single Element Strain Gage.......................................................................36 Figure 17: Strain Gage Attachment.............................................................................37 Figure 18: Wide-Range Strain Indicator (Model 3800)...............................................38 Figure 19: Placement of Strain Gage on Wound Roll.................................................39 v Figure 20: Collection of Experimental Strain Data.....................................................40 Figure 21: Measurement of Pile Height.......................................................................41 Figure 22: MD Strains in 6 inch Wide PET.................................................................47 Figure 23: CMD Strains in 6 inch Wide PET..............................................................49 Figure 24: MD Strains in 24 inch Wide PET...............................................................51 Figure 25: CMD Strain in 24 inch Wide PET..............................................................53 Figure 26: MD Strain Comparison..............................................................................54 Figure 27: CMD Strain Comparison............................................................................55 Figure 28: Bending Strain Diagram.............................................................................59 Figure 29: MD Strain for 6 inch Wide Web................................................................61 Figure 30: CMD Strain for 6 inch Wide Web..............................................................62 Figure 31: MD Strain for 24 inch Wide Web..............................................................63 Figure 32: CMD Strain for 24 inch Wide Web............................................................64 Figure 33: Depth of Gage in Wound Roll Example Plot.............................................65 Figure 34: MD Strain for 6 inch Wide Web for Comparison with Experimental Results ................................................................................................................................66 Figure 35: CMD Strain for 6 inch Wide Web for Comparison with Experimental Results ................................................................................................................................67 Figure 36: MD Strain for 24 inch Wide Web for Comparison with Experimental Results ................................................................................................................................67 Figure 37: CMD Strain for 24 inch Wide Web for Comparison with Experimental Results ................................................................................................................................68 Figure 38: Theoretical and Experimental MD Strains for 6 inch Wide Web..............69 Figure 39: Theoretical and Experimental CMD Strains for 6 inch Wide Web...........70 Figure 40: Theoretical and Experimental MD Strains for 24 inch Wide Web............71 vi Figure 41: Theoretical and Experimental CMD Strains for 24 inch Wide Web.........72 Figure 42: Theoretical and Average Experimental Comparison of MD Strains for 6 inch Wide Web..............................................................................................................73 Figure 43: Theoretical and Average Experimental Comparison of CMD Strains for 6 inch Wide Web..............................................................................................................74 Figure 44: Theoretical and Average Experimental Comparison of MD Strains for 24 inch Wide Web..............................................................................................................75 Figure 45: Theoretical and Average Experimental Comparison of CMD Strains for 24 inch Wide Web......................................................................................................76 vii LIST OF SYMBOLS AND ABBREVIATIONS PET Polyester Film WHRC Web Handling Research Center HSWL High Speed Web Line MD Machine Direction CMD Cross Machine Direction pli pounds per linear inch fpm feet per minute E Radial Young’s modulus r E Tangential Young’s modulus θ σ Radial stress r σ Tangential stress θ σ Axial stress z ε Radial strain r ε Tangential strain θ ε Axial strain z r Radius d Diameter ν Poisson’s ratio of stress in θ-direction to strain in r-direction rθ ν Poisson’s ratio of stress in r-direction to strain in θ-direction θr ν Poisson’s ratio of stress in r-direction to strain in z-direction zr viii ν Poisson’s ratio of stress in z-direction to strain in θ-direction θz P Normal pressure K Material constant 1 K Material constant 2 δ Level of interference ij u, u Nodal points i j T Web tension w t Web thickness w Web width α Reinforcement factor R Outer radius of core outer G Shear modulus rz Y Distance of neutral axis R Radius of curvature ε (r) Tangential strain at certain radius, r θ ε (r) Axial strain at certain radius, r z ε (gage) Tangential strain at gage’s radius θ ε (gage) Axial strain at gage’s radius z ix CHAPTER I INTRODUCTION TO STRESSES IN WOUND ROLLS Web materials are very common in manufacturing environments today and will continue to be in the future. A web is defined as a material whose length is much greater than its width and whose width is much greater than its thickness. Webs can be made of just about anything. Several common categories of web materials include paper, plastic films, metal foils and laminates. Hundreds of thousands of products are made from these webs and webs encompass many of the products used in daily life. In manufacturing environments, wound rolls of web material are often the most economical and practical solution for material storage and transportation. Unfortunately, this is not without several problems. Just the act of winding the web can cause damage of several kinds to the web. This damage has been the topic of numerous research studies. The quality of the wound roll depends on the stresses which exist in it. While these in-roll stresses determine the structural integrity of the roll, they can also impart damage onto the roll. If these stresses are allowed to go uncontrolled, the results are tearing and buckling along with many other defects in the wound material. 1
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