Wood is characterized by excellent vibration damping, low material density and electromagnetic compatibility. Veneer laminates have a particularly high potential in this respect, as the combination of individually oriented veneer layers allows the properties of the laminate to be adjusted to the specific application requirements. Portable camera tripods require good vibration damping to avoid blurry images, as well as light weight and small pack size. In this project, veneer tube structures were developed to reduce the weight and pack size of an existing wooden camera tripod while improving the damping characteristics.
Experimental characterization of stiffness and strength parameters for different species of wood with focus on the effect of fiber orientation on the mechanical properties were carried out. Particular attention was paid to the damping characteristics, which were determined by Dynamic Mechanical Analysis (DMA) in a 3-point bending setup (variation of wood species, fiber orientation, temperature, excitation frequency). The characteristic values obtained from mechanical testing were used to numerically design the stiffness and strength behavior of the tripod tube structures. The stiffness and strength requirements were validated experimentally. Vibration measurements on the assembled tripod demonstrated a significantly improved damping behavior.
The calculation approaches used here for modelling damage initiation (adapted failure criterion for fiber reinforced polymers based on Cuntze) shall be transferred to similar veneered structures with a more complex loading situation in future. A special focus will be on fatigue damage behavior under cyclic loading. For this purpose, existing models developed for fiber composites will be briefly presented along with a discussion of their transferability to veneer laminates.