SUPERVISOR: Ulrich MÜLLER

PROJECT ASSIGNED TO: Maximilian PRAMREITER

Abstract:
The project aims at the investigation of mechanics and composition of wood tissues at several hierarchical levels as well as the optimized shape and internal structure biological structures. Following a biomimetic approach the potential of wood material should be imitated in composites by using artificial and biological fibres. Understanding of the biological structure, the investigation of new composites and connections and the development of connection to other materials will strongly supported by numerical methods.

Initial state:
The institute for wood technology and renewable materials has been investigated the structures of the stem-branch connection for several years. In cooperation with Prof. Jozef Keckes (Erich Schmid institute, Leoben) several papers describing the mechanical and structural properties and the complex structures surrounding the stem-branch connection have already been published. This specific biological system shows a mechanically optimized structure, which allows the branches to withstand high loads and to fulfil physiological functions. Furthermore, this complex system provides predetermined breaking points and extreme ductile behaviour. Even under stresses higher than the yield strength the structure is never completely destroyed. Only under very high deformation disintegration occurs. Better knowledge of the structure should be used to develop advanced connections with high load capacity and increased ductile behaviour at overload.

Within the scope of the project WoodC.A.R. numerical methods like Finite Element Modelling (FEM) are used to develop new applications for wood based composites. Additionally, predictability of wood at failure as well as new production and production processes of fibre reinforced wood materials should be investigated. Reinforcement and connection of vehicle parts by the means of natural and artificial fibre reinforced composites is not part of this project. 

Goals:
The aim of the present dissertations is to further investigate the natural building principles of the stem-branch connection and the application of these principles to the connection technologies of the automotive industry. In addition to further anatomical investigations first physical models should be established using natural and artificial fibre reinforced composites. The behaviour of these models are investigated using mechanical testing and numerical simulation (e.g. FEM). Based on the results new technical solutions for the connection of wood based composites with other materials will be implemented within WoodC.A.R. and other projects of the partner company Weitzer Parkett.

In addition to the investigation of the stem-branch connection numerical methods for Finite-Element-Modelling should be established within the working group of Prof. Müller as well as within the partner company Weitzer Parkett this will also intensive the scientific cooperation furthermore.
An additional aim of this dissertation is therefore the implementation of these methods within both institutions.