Film project for educational purposes: "Failure mechanisms in timber structures"

 

Exemplary Film 1:  Tension parallel to the Grain
Exemplary Film 2:  Dowel-Type Connection

The use of new forms of media for educational purposes has become indispensable. Interactive teaching methods already enrich a variety of courses of study and training programs. For this reason, the Chair of Timber Structures and Building Construction at the Technische Universität München has started a project with the title "Failure mechanisms in timber structures" in cooperation with the Bundesbildungszentrum des Zimmerer- und Ausbaugewerbes in Kassel. The objective was to realize a comprehensive library of short films to visualize the characteristic failure mechanisms in timber and timber connections which result from the particular material properties of this natural and anisotropic building material.

Experiments were performed on structural elements or scaled test specimen. In addition to a video camera, a high speed camera was used to capture a detailed image of brittle failure modes in wood. In some cases, the film recordings were combined with contact-free measurements or load-deformation curves to better visualize the magnitude and distribution of stresses in the test specimen.
All fundamental material properties of wood were visualized, including tension, compression, bending and shear. Beams in bending were used to demonstrate the effect of e.g. notches and holes, or to portray topics like stability and dynamic behavior. Furthermore, all failure modes of dowel type fasteners are visualized as well as the behavior of common carpentry connections. The contents of the DVD can be viewed here:

DVD Booklet .

The 52 films shall foster a better understanding of the typical mechanical properties of timber and its differences to other building materials. The videos are well suited as teaching material and can be used to supplement education in the field of construction.

Exemplary pictures from the films as well as weblinks to two films.

Figure 1: Detail of Specimen failing in Tension parallel to the Grain at the Tips of the Finger Joint
Figure 2: Detail of Specimen failing in Compression parallel to the Grain
Figure 3: Detail of Specimen failing in Compression perpendicular to the Grain
Figure 4: Detail of Specimen failing in Bending
Figure 5: Detail of Dowel-type Connection – Plastic Hinges in center and side Members
Figure 6: Detail of Step Joint failing in Compression at an Angle to the grain

 

A DVD with all videos (German and English) can be purchased at the Chair of Timber Structures and Building Construction for a contribution towards expenses of € 39.90.

Project Leaders:
Dipl.-Ing. Philipp Dietsch
Andreas Gamper M.Sc.
Dipl.-Ing. Michael Merk

Joint editor:
Bundesbildungszentrum des Zimmerer- und Ausbaugewerbes
Dr.-Ing. Holger Schopbach