Abstract
The use of tropical hardwoods in structural applications requires knowledge of the mechanical properties. Even though long experience is available with the species azobé (Lophira alata), much of the current knowledge is based on tests performed on small clear specimens for bending, compression and shear. Since tropical hardwoods are used in structures with high economic value, a sound knowledge of the mechanical properties allows for better optimisation and for minimal use of raw material. Bending, compression and shear tests have been performed on material in structural sizes. Characteristic values show that in most loading cases the structural capacity of the material is distinctly higher than currently assumed in practice. The relationship between static modulus of elasticity and bending strength has been determined. The depth effect was shown to be less pronounced than for softwoods.
Zusammenfassung
Der Einsatz von Konstruktionsholz aus tropischen Hölzern setzt die Kenntnis der mechanischen Eigenschaften dieser Hölzer voraus. Obwohl Bongossi seit vielen Jahren als Bauholz vor allem in bewitterten Konstruktionen verwendet wird, wurden mechanische Kennwerte für Biege-, Druck- und Scherbeanspruchung vor allem aus der Prüfung kleiner fehlerfreier Prüfkörper abgeleitet. Da tropische Hölzer überwiegend in ökonomisch bedeutenden Konstruktionen eingesetzt werden, erlaubt eine bessere Kenntnis der mechanischen Eigenschaften optimierte Konstruktionen sowie Einsparungen insbesondere beim Rohstoff. In dieser Arbeit wurden Biege-, Druck- und Scherversuche mit Prüfkörpern in Bauholzabmessungen ausgewertet und die entsprechenden charakteristischen Steifigkeits- und Festigkeitskennwerte bestimmt. Die Ergebnisse zeigen, dass Bongossi bessere mechanische Eigenschaften aufweist als bisher angenommen. Die Beziehung zwischen statischem Elastizitätsmodul und Biegefestigkeit wurde bestimmt. Der Höheneinfluss von Bongossi zeigte sich weniger ausgeprägt als für Nadelholz.
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van de Kuilen, J.W.G., Blass, H.J. Mechanical properties of azobé (Lophira alata). Holz Roh Werkst 63, 1–10 (2005). https://doi.org/10.1007/s00107-004-0533-7
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DOI: https://doi.org/10.1007/s00107-004-0533-7