A novel manufacturing process for timber-filled tubes and performance evaluation of the formed tubes

Timber-filled tubes (TFTs) have gained attention in the construction industry due to their potential to replace concrete-filled tubes since TFTs have good compressive properties and ecological benefits. However, TFTs are mainly manufactured by craft production, which limits their wide adoption in construction. This paper proposes automating the TFT manufacturing process by using the existing tube sinking process. Circumferential compression in the tube sinking process should restrain the wood within the metal tubes while reducing production time and achieving wood densification. Experiments are performed on a TFT composed of aluminium and wood. Two forming steps are performed on the TFTs to attain the desired component diameters. Results of the process reveal improved mechanical properties for the TFT compared to either of the constituents. A production rate of 2 m/min was used in the experiments. Finite element simulations of the novel process reveal that the deformation mechanism of the aluminium in the TFT is similar to tube sinking, and the wood is deformed by biaxial compression. The forces in FE simulations of TFT sinking are higher than in the sinking of the aluminium tube by about 20 kN, which demonstrates that most existing production lines can be used to form TBT without the need for major retooling.