A plate model for compressive strength prediction of delaminated composites. (15th February 2019)

• Record Type: Journal Article
• Authors: Choudhry, Rizwan S.; Rhead, Andrew T.; Nielsen, Mark W.D.; Butler, Richard
• Is Part Of: Composite structures. Volume 210(2019)
• Page Start: 509
• Page End: 517
• Publication Date: 2019-02-15
• Subjects: Damage tolerance -- Delamination -- CAI -- Modelling -- Impact -- Buckling; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2018.11.066
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: Damage tolerance is of critical importance to laminated composite structures. In this paper, we present a new semi-analytical method for predicting the strain at which delamination propagation will initiate following sublaminate buckling. The method uses a numerical strip model to determine the thin-film buckling strain of an anisotropic sub-laminate created by delamination, before evaluating the strain energy release rate for delamination propagation. The formulation assumes that all energy is available for propagation in a peeling mode (Mode I); avoiding an approximate mixed-mode criterion. Results are compared with twelve experimentally obtained propagations strains, covering a variety of laminates each containing a circular PTFE delamination. Comparison shows agreement to within 12% for balanced sublaminate tests in which delamination propagation occurred before intra-ply cracking. The method can be used to significantly improve the damage tolerance of laminates, opening up new opportunities for structural efficiency using elastic tailoring, non-standard ply angles and material optimisation.