Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2012 The effect of tow grouping resolution on shearing deformation of unidirectional non-crimp fabric Wade Johanns Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Industrial Engineering Commons Recommended Citation Johanns, Wade, "The effect of tow grouping resolution on shearing deformation of unidirectional non-crimp fabric" (2012). Graduate Theses and Dissertations. 12720. https://lib.dr.iastate.edu/etd/12720 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. i The effect of tow grouping resolution on shearing deformation of unidirectional non-crimp fabric by Wade Walter Johanns A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Industrial Engineering Program of Study Committee: John Jackman, Major Professor Vinay Dayal Matthew Frank Frank Peters Iowa State University Ames, Iowa 2012 Copyright © Wade Walter Johanns, 2012. All rights reserved. ii Table of Contents List of Figures ....................................................................................................................................... iv List of Tables .......................................................................................................................................... v Acknowledgements ............................................................................................................................... vi Abstract ................................................................................................................................................ vii Chapter 1. Introduction ........................................................................................................................... 1 Background ........................................................................................................................................ 1 Chapter 2. Related Research................................................................................................................... 9 Fabric Draping and Shearing .............................................................................................................. 9 Automated Fabric Deposition........................................................................................................... 14 Research Problem ............................................................................................................................. 17 Research Questions .......................................................................................................................... 19 Approach .......................................................................................................................................... 19 Chapter 3. Methodology ....................................................................................................................... 21 Description ....................................................................................................................................... 21 Draping Simulation .......................................................................................................................... 21 Shearing Apparatus .......................................................................................................................... 23 Mold Geometry ................................................................................................................................ 26 Shearing Relaxation Compensation ................................................................................................. 27 Experiment ....................................................................................................................................... 28 Objective ...................................................................................................................................... 28 Independent Variable.................................................................................................................... 28 Dependent Variable ...................................................................................................................... 29 Draping Simulation and Profile Approximation .......................................................................... 29 Pre-shearing Process ..................................................................................................................... 31 Shearing Misalignment Compensation ......................................................................................... 33 Fabric Deposition ......................................................................................................................... 33 Data Acquisition ........................................................................................................................... 34 Data Analysis ............................................................................................................................... 35 Chapter 4. Results ................................................................................................................................. 39 Repeatability of Pre-shearing ........................................................................................................... 39 Feasibility of Low Resolution Pre-Shearing .................................................................................... 42 iii The Effect of Tow Grouping Configuration on Out-of-plane Deformations ................................... 43 Chapter 5. Conclusions ......................................................................................................................... 48 Repeatability of Pre-shearing ........................................................................................................... 48 Feasibility of Low Resolution Pre-shearing ..................................................................................... 49 The Effect of Tow Grouping on Out-of-plane Deformations ........................................................... 49 General Conclusions and Future Work ............................................................................................ 50 References ............................................................................................................................................ 52 iv List of Figures Figure 1. Crimp and non-crimp fabric. ................................................................................................... 2 Figure 2. Out-of-plane deformations: a wave and a wrinkle. ................................................................. 4 Figure 3. In-plane shear deformation of a pin-jointed net unit cell (Gutowski 1997) ............................ 6 Figure 4. An illustration of a shear angle distribution.. ......................................................................... 7 Figure 5. Experimental results of fabric shearing (Lin et al. 2007). ..................................................... 10 Figure 6. The process of shearing a stitched non-crimp fabric ............................................................ 11 Figure 7. Automated Fiber Placement (Debout 2011) ......................................................................... 15 Figure 8. The process of a conceptual automated "shifting" head (Magnussen 2011). ........................ 17 Figure 9. Simulation parameters for a doubly curved mold. ................................................................ 22 Figure 10. A color map of the shear angle ........................................................................................... 22 Figure 11. A draping simulation output. .............................................................................................. 23 Figure 12. Tow displacement profiles .................................................................................................. 24 Figure 13. The fiberglass fabric placed into the shearing device ......................................................... 25 Figure 14. A simplified depiction of the shearing device. .................................................................... 25 Figure 15. The pre-shearing apparatus ................................................................................................. 26 Figure 16. The toroidal section mold. .................................................................................................. 27 Figure 17. The tow-displacement profile required to pre-shear the fabric ........................................... 30 Figure 18. Fabric clamping proceedure prior to the first displacement ................................................ 30 Figure 19. Measuring tow group displacement .................................................................................... 31 Figure 20. The first three steps of the pre-shearing process for a symmetric profile. .......................... 32 Figure 21. The tow misalignment after the initial displacement .......................................................... 33 Figure 22. The pre-sheared fiberglass ply is