Experimental study on the panel size effects of the Low-Velocity Impact (LVI) and Compression After Impact (CAI) of laminated composites, Part I: LVI. (15th September 2022)

• Record Type: Journal Article
• Authors: Lin, Shiyao; Ranatunga, Vipul; Waas, Anthony M.
• Is Part Of: Composite structures. Volume 296(2022)
• Publication Date: 2022-09-15
• Subjects: Low velocity impact -- Panel size effects -- Laminated composites; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2022.115822
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: An experimental study of the LVI responses of flat composite panels of different in-plane sizes is reported in this paper. The studied samples vary in the in-plane size, thickness, and stacking sequence. The three studied in-plane sizes are 152.4 mm × 101.6 mm, 177.8 mm × 177.8 mm, and 330.2 mm × 330.2 mm. The two thicknesses are 24-ply and 48-ply. The two stacking sequences are [45/-45/0/90/0/0]ns and [45/0/-45/90]ns . The material system is IM7/977-3. Experimental results including load responses, 3D digital image correlation (DIC), surface inspections, ultrasound C-scanning, and X-ray μ CT are presented. It is found that the studied layups (two) have little effect on the load responses but change the LVI-induced damage morphology significantly. The thickness-to-length/width ratio is identified as the most important geometric parameter influencing the LVI responses and damage. However, the investigated panel size effects are only on the load responses and damage sizes, but not on the detailed damage features characterized by μ CT, implying that the LVI damage mechanisms are unaffected. The panel size effects reported in this paper show that the existing industrial standard (ASTM D7136, 2005) that focuses on single-size (152.4 mm × 101.6 mm) samples may require revision as demonstrated in part II of this two-part paper.