banner.jpg 287 Damage Analysis of Curved Composite Structures Using Interface Elements Raju1,2,3,a, David Lyons2,b and Prusty BG2,c 1QuEST Global Engineering, Bangalore, India. arajuaero@yahoo.com 2School of Mechanical and Manufacturing Engineering, UNSW, Australia. bdavid.lyons@unsw.edu.au cg.prusty@unsw.edu.au 3Department of Aeronautical Engineering, New Horizon College of Engineering, Bangalore, India. ABSTRACT

This paper presents the finite element (FE) analysis of top hat stiffeners (manufactured using vacuum assisted resin transfer moulding (VARTM)) under static load where splitting/delamination is the primary mode of failure. A set of experiments are conducted on composite top hat stiffeners with three different layup arrangements. The experimental study together with FE modelling to capture the delamination failure is presented. Fracture initiation is predicted using an inter-laminar strength-based criterion. A fracture mechanics-based formulation is used to predict the delamination propagation by connecting the composite layers with 2D/3D interface elements. A reasonable agreement between the experiment and finite element analysis has been observed. Factors affecting the fibre-matrix interface strength were studied. The failure location and failure mode for fracture initiation and propagation are determined.

Keywords: Curved composites, Delamination, Progressive failure analysis, Cohesive zone element.

pdflogo.jpg 287