The document describes a study on the effect of holes on the tensile strength of composite materials created through hand layup. It outlines the goals to develop a hand layup procedure and test how holes influence composite strength. The methodology section explains the hand layup process and sample preparation/testing. Results show the material's properties are lower than expected and holes reduce strength. The characteristic length, over which stresses average around a hole, is calculated to be approximately 0.133 inches.

1. Hand layup procedure and effect of holes on composite strength Paul Peavler 4/22/2010

2. Outline Background -motivation Goals and Objectives -develop hand layup procedure -test effect of holes on composite tensile strength Methodology -hand layup equipment and procedure -sample preparation and testing Results, analysis, and discussion -laminate layup -characteristic length of open hole composites Conclusions -material differences

12. Results & Analysis

13. Results & Analysis

14. Results & Analysis

17. Questions?

18. Appendix

19. Appendix

20. Appendix

21. Appendix

22. Appendix Cure cycle Segment Force Dwell Time Temp SP 1 Temp SP 2 1 4300 lb 5.2 min 96 °F 96 °F 2 4300 lb 5.3 min 122 °F 122 °F 3 4300 lb 5.2 min 149 °F 149 °F 4 4300 lb 5.3 min 175 °F 175 °F 5 4300 lb 5 min 175 °F 175 °F 6 4300 lb 5 min 175 °F 175 °F 7 4300 lb 5 min 175 °F 175 °F 8 4300 lb 5 min 175 °F 175 °F 9 4300 lb 3.7 min 194 °F 194 °F 10 4300 lb 3.8 min 212 °F 212 °F 11 4300 lb 3.7 min 231 °F 231 °F 12 4300 lb 3.8 min 250 °F 250 °F 13 4300 lb 22.5 min 250 °F 250 °F 14 4300 lb 22.5 min 250 °F 250 °F 15 4300 lb 22.5 min 250 °F 250 °F 16 4300 lb 22.5 min 250 °F 250 °F 17 4300 lb 15 min 60 °F 60 °F 18 4300 lb 15 min 60 °F 60 °F 19 4300 lb 15 min 60 °F 60 °F 20 4300 lb 15 min 60 °F 60 °F

23. Appendix Measured sample dimensions Sample 1 width (in) Sample 1 thickness (in) Sample 2 width (in) Sample 2 thickness (in) 0.992 0.103 1.003 0.102 1.008 0.102 0.999 0.104 1.002 0.102 0.999 0.100 1.020 0.102 0.993 0.100 1.239 0.103 1.232 0.102 1.237 0.102 1.235 0.102 1.241 0.103 1.229 0.101 1.243 0.103 1.239 0.104 1.474 0.101 1.477 0.1 1.476 0.1 1.466 0.101 1.457 0.101 1.478 0.099 1.44 0.103 1.464 0.102

24. Appendix Finite width corrections and stresses K/K ∞ σ n1(∞) σ n2(∞) 1.0405649 56738.046 59500.726 1.0763889 52437.059 54778.277 1.1272491 0 55386.45 1.196875 50533.816 51797.091 1.0251471 54613.326 61380.568 1.0466667 54150.052 53329.743 1.0763889 52983.884 51131.622 1.1157143 53459.699 48649.43 1.0171131 56040.374 58230.459 1.0314815 55474.389 56806.379 1.0510173 50840.143 54730.015 1.0763889 54269.448 54259.951