Timber in Braced and Cable Stayed Spatial Structures

The aim of this paper is to overview the development of co-action between timber elements and other materials in composite spatial structures, thereby highlighting the impact and usability of composite structures. The basic principles are rather simple approaches to exploiting tensile and compressive strengths of utilised materials. Among the engineers providing to this structural development are the French engineer Camille Polonceau (1813- 1859) developing roof trusses and the engineer Albert Fink (1827-1897) who was borne and educated in Germany, and professionally active in the US with development of trussed bridge structures. Later examples related to the works of Polonceau can be seen in e.g. roof trusses for equestrian halls. Fink trusses have become rare in bridges but more widely used in roof structures. However, an example of a Fink truss bridge from the late 1990’s was constructed in Katch an der Mur, Austria. This pedestrian bridge utilises subdivision of the span to transfer the forces along the deck without intermediate props. Hereby it relates to cable-stayed elements as well as to structural types like tensegrity. The development of cross-laminated timber plate elements has increased the potential of co-action between timber members and cables in spatial structures and some recent applications of this co-action are discussed.