Meshfree methods for low velocity impact analysis of composites

For a few decades, composite materials have been successfully used as structural materials, replacing not only steel but even light alloys in the construction of some parts of vehicles, spaceships and airplanes. These materials are subjected to a wide specimen of loadings during in-service use and impact loadings represent a serious design condition in the case of laminated composites. In fact, composites are more susceptible to impact damages than similar metallic structures. If a composite laminate is subjected to normal lowvelocity impact, invisible damages consisting of internal delamination, fibre or matrix failure might be induced. Therefore, for an effective design of composite structures, it becomes very significant to understand the impact induced damage mechanisms, which have been treated in numerous experimental and analytical investigations. As a promising counterpart of mesh-based methods, meshfree formulations are developing rapidly in various fields of computational mechanics, e. g., in static analyses, free vibration analyses, fracture mechanics, fluid dynamics, soil-structure interaction and in the solution of helmholtz equations for acoustic problems. However, up to now only very few attempts have been taken to analyze composites using these approaches. In the present thesis, the radial point interpolation method (RPIM) has been rigorously studied and further developed to investigate the extent of low-velocity impact induced damages in composites.