Moulded wood profiles from solid wood are novel structural elements for architecture, civil and mechanical engineering. The idea is based on wood as a cellular material that undergoes large deformations when heated and compressed. With the help of moisture and temperature the deformation can be released and used for shaping [1].

The presentation will show the thermo-hygromechanical behaviour of wood and its particularities such as recovery when moistened and fixation when dried. For structural use wooden tubes can optionally be reinforced with technical fibres and textiles from glass, aramid and carbon.

Within this research particular attention is paid to the use soft and hardwood such as beech. It could be shown that this specie is suitable for moulding perpendicular to the grain. Consequences regarding sylviculture and environment are being discussed.

Experimental test results of components and connections will be presented as well as environmental impact assessments.

Structural tubes showed outstanding load bearing capacities. Special applications from the building sector and plant engineering such as solar and wind power stations are also dealt with. Within the project BEECHPOLE, a lightning pole is being developed [2] [3]. The study of its impact behaviour on a test track with a car showed excellent results regarding the frangibility criteria.

The same physical principles are used for the shaping of sandwich cores from wood, especially Balsa. This approach uses end grain panels from bi-axially compressed wood that allow the manufacturing of double curved shells. In addition with high performance fibres one obtains sandwich elements with a high potential in lightweight design.

Keywords: Wood, moulding, fibre reinforced profiles

References
[1] KUTNAR, A.; SANDBERG, D.; HALLER, P.;: Compressed and moulded wood from processing to products – a review; Holzforschung, 01/2015
[2] J. U. HARTIG; J. WEHSENER; P. HALLER; Experimental and theoretical investigations on moulded wooden tubes made of beech (Fagus sylvatica L.) Construction and Building Materials 126 (2016) 527–536
[3] J. U. HARTIG; S. FACCHINI; P. HALLER; Investigations on lateral vehicle impact on moulded wooden tubes made of beech (Fagus sylvatica L.) Construction and Building Materials 174 (2018) 547–558

Prof. Dr.-Ing. Peer Haller