Issue 39

M.A. Tashkinov, Frattura ed Integrità Strutturale, 39 (2017) 248-262; DOI: 10.3221/IGF-ESIS.39.23 248 Modelling of fracture processes in laminate composite plates with embedded delamination Mikhail A. Tashkinov Perm National Research Polytechnic University, Russia m.tashkinov@pstu.ru A BSTRACT . This work is devoted to research and development of models for the processes of nucleation and growth of delamination in laminated composite materials. Possibilities of fracture mechanics approaches using virtual crack closure technique as well as progressive failure analysis based on the failure criteria are demonstrated. Influence of the initial delamination size on the rate of growth of the defect is studied. A comparative analysis of the applicability of fracture criteria to modeling of samples with delamination were performed, including implementation of element deletion algorithm. The numerical results obtained with the studied methods were compared. K EYWORDS . Composite laminates; Delamination; VCCT; Progressive failure analysis; Fracture criteria; Element deletion. Citation: Tashkinov, M. A., Modelling of fracture processes in laminate composite plates with embedded delamination Frattura ed Integrità Strutturale, 39 (2017) 248-262. Received: 01.11.2016 Accepted: 21.11.2016 Published: 01.01.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION omposite materials are widely used in demanding and high-performance applications, largely due to their relatively high strength and stiffness and, at the same time, low weight and density. However, these materials are affected by development of internal defects caused by the peculiarities of their microstructure. To predict the behavior of composites under operational loads, an important and urgent challenge is to develop numerical approaches for description of the processes of accumulation of damage and subsequent failure of the materials. Modelling of failure processes is challenging, especially for the composite materials, due to the specifics of their microstructure. One of the most common types of composite materials are laminated composites. Their numerical simulation usually considers several scale levels: • micro-scale, where the constituents that composing a representative volume of the material can be distinguished (fiber and matrix); • ply scale, which consists of fibers, stacked in a certain way, and linking matrix. Usually a separate ply has orthotropic or transversal-isotropic properties. • laminate scale, which is formed by superimposing of several plies with different fiber orientations. Depending on the stacking of plies, the laminate may possess anisotropic, orthotropic or quasi-isotropic properties. For simplicity, the effective properties of the laminate describing homogeneous behavior are often used in calculations. C