WOOD RESEARCH Volume 67, Number 2, 2022
ARIF CAGLAR KONUKCU

Determination of mode I fracture behavior of southern yellow pine (Pinus taeda L.) wood using single-edge-notched bending test

The fracture behavior of southern yellow pine (Pinus taeda L.) was experimentally analyzed in the radial-longitudinal and the radial-tangential crack propagation systems using a single-edge-notched bending test method in mode I loading condition. Three fracture parameters, the initial slope, the fracture toughness, and the specific fracture energy, were determined from the obtained load-deformation curves of each test sample. The results were statistically analyzed and compared with each other using the independent samples t-test. The radial-longitudinal crack propagation system had a significantly greater fracture toughness than in the radial-tangential crack propagation system. The stiffness in the radial-longitudinal system was also significantly higher than in the radial-tangential system. It was observed that the crack growing in the tangential direction needed more energy per unit area to separate a wood sample into two halves. However, there was no significant difference between the specific fracture energy values of crack propagation systems.

WOOD RESEARCH Volume 67, Number 1, 2022
Maharshi J. Dave, Tejas S. Pandya, Suman Babu Ukyam, and Jason Street

Short notes: The low-velocity impact response of bio-composites

In this paper, an experimental investigation on the low-velocity impact response of wood-based bio-composites is presented. This study is to map the suitability of plant-based materials instead of petroleum-based plastic as a constituent raw material in composites. Wood-based composites panels were made from southern yellow pine (SYP), corn starch (CS), and methylene diphenyl diisocyanate (MDI) using a Diefenbacher hot press. The impact performance of the specimens was evaluated in terms of energy absorption capacity. Five types of bio-composites were prepared with varying compositions with SYP: 4% MDI; 2% CS and 2% MDI; 2% CS and 4% MDI; 4% CS and 4% MDI. These samples were prepared at two different manufacturing pressures. The bio-composite produced with higher manufacturing pressure had the highest absorbed energy among five different types of bio-composites, this shows that material behavior at impact loading is strongly dependent on the manufacturing pressure during fabrication.