Variability of Marine Composite Properties in a Manufacturing Round Robin Study
Publication Name: Proc. of the 53rd Int. SAMPE Symposium and Exhibition, Material and Process Innovations: Changing our World, CD-ROM, ISSE Vol. 53, 18 pp., May 18-22, Long Beach, CA, 2008.
Publication URL: https://www.nasampe.org/store/viewproduct.aspx?id=4370718
Presented in this paper are the results of the tension and compression testing from a round-robin manufacturing study. The study was part of an ongoing Office of Naval Research project to determine the causes of material property variability of E-glass/vinyl ester composites fabricated with a VARTM process. The manufacturers consisted of five industrial composite fabricators that either had experience with US Naval fabrication projects, or possessed commercial marine fabrication experience. The materials specified for the study were a 24oz woven-roving E-glass fabric with a rubber-toughened vinyl ester resin system. The study included material coupon testing and structural flexural testing, however only the results of the tension and compression coupon testing are presented here. The standardized material coupon tests were performed on cross-ply laminates in a warps parallel lay-up. The determination of strain using conventional strain gages can be problematic for heavy woven fabrics, due to tow size and weave pattern, therefore the strain of the material coupon specimens was recorded using a 3D digital image correlation (DIC) system. The results of the testing, including the statistical analysis procedure used, are presented for each test type and manufacturer.