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Gewählte Doctoral Thesis:

Aleksandra Sretenovic (2004): Mechanics of wood and wood-fibre composites - optimisation of shear testing and stress transfer in a single fibre composite.
Doctoral Thesis, BOKU-Universität für Bodenkultur, pp 102. UB BOKU obvsg

Data Source: ZID Abstracts
Mechanical behaviour of solid wood and wood composites is related to the material structure at the microscopic and molecular level. The response is, on the other side, manifested macroscopically. This was demonstrated through the study of optimisation of shear testing of solid Spruce and Larch wood, comparative study of testing plywood and OSB in five-point bending tests and EN 789 shear tests for shear strength determination, and the study performed for definition and characterising the connection type between wood fibres and surrounding polymer matrix in wood- plastic composites. For numerical validation of experimental results finite element analysis was performed. A homogeneous shear stress distribution was revealed by FE analysis in a new shear test set-up specimen where stress state was fairly close to the stress state required for the determination of shear strength and shear modulus. In EN 789 specimens of plywood and OSB, shear stresses were also homogeneously distributed, while typical s-shaped stress fields were observed in beam sections of five-point bending specimens. The distribution of strains in a single wood fibre-reinforced low density polyethylene composite was observed by means of Elctronic Laser Speckle Interferometry (ESPI). Again FE analyis confirmed experimental results. It indicated a significant transfer of stress from the marix to the fibre via fibre ends.

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