New formulas for calculating mode II fracture energy of several typologies of GRP pipes under impact. (1st May 2016)

• Record Type: Journal Article
• Authors: Marco-Ayala, C.; Marco, C.J.; Salete, E.
• Is Part Of: Composites. Volume 92(2016)
• Page Start: 242
• Page End: 251
• Publication Date: 2016-05-01
• Subjects: A. Layered structures -- B. Impact behaviour -- C. Analytical modelling -- D. Mechanical testing; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2016.02.041
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: The authors suggest a simple monomial formula to determine the delamination starting energy U 0 under impact in GRP pipes with sand filled layer. By means of analytical procedures, deducted from the Mechanically Contaminated Layer Theory, a new equation in mode II of fracture, unique for all types and different manufacturers is developed. The shape of this equation adjusts in a 98.96% of the observed law and mainly depends on the square of the height of the tube and its resistance to internal hydraulic pressure, achieving numerical errors, using a general theoretical coefficient, of less than 10% for pipes of very different kinds, that can be improved using empirical coefficients customized for each manufacturer. Thus, it facilitates technicians with a practical design tool against the invisible effects of a blow and warrants seriously rethinking the current design criteria that does not take into account the brittleness of an impact.