Budapesti Műszaki és Gazdaságtudományi EgyetemÉpítőmérnöki Kar - építőmérnök képzés 1782 óta

Composite materials play an increasing role in engineering. In structural engineering, fibre reinforced plastics (FRP) composites are used in various applications. They are made of high-strength fibres (mostly carbon or glass) embedded in a matrix (mostly epoxy), and provide formidable strength in fibre direction. Applications include reinforcement of structural elements made of other materials, such as concrete, steel, timber in order to enhance structural behaviour. The combined behaviour of such composite structures requires both theoretical research and practical application experience. Research on reinforcement of timber include experimental work on old or new timber structures, analytical and numerical computations, and other special problems. The inhomogeneous, nonlinear, and highly anisotropic nature of wood as well as the inherent inhomogeneous characteristics of FRP materials pose major challenges in research. Since most researchers focus on a single or sometimes a few wood species, especially those locally available or significant in the local industry, the results represent a large spectrum, and sufficient data are not available in some cases.

The proposed research deals with Norway spruce, a species native to the region and plays an important role in timber construction. The behaviour of solid sawn spruce beams fitted with carbon fibre reinforced plastic (CFRP) sheets are to be analysed. Measurement data are available from physical experiments performed with four-point bending loading on a large sample. The aim of the research is to do finite element modelling of the behaviour of both the wood material and the reinforcement material using the measurements for verification. The modelling is focusing on the details on various levels. The composite structure of the fibre reinforced plastic needs to be modelled both as a homogenised piece on the large scale and as a compound of various constituents to identify key factors in the behaviour. The wood material is naturally inhomogeneous, anisotropic, and contains randomly distributed features influencing the behaviour, such as knots or other defects. Modelling on different levels should incorporate appropriate handling of material properties and anisotropy as well as modelling techniques. The task requires the application of finite element software, e.g. ANSYS and numerical tools, e.g. MATLAB. The expected outcome of the research is to gain deeper understanding and modelling capability of Norway spruce beams reinforced with CFRP lamellae on various levels.