Scientific publications
Charly Julien Nyobe* (Corresponding author)
Other affiliations: University of Douala · Institute of Technical Education
Nicolas Stéphane Nyobe
Louis Max Ayina Ohandja
Wood Material Science and Engineering
Tali wood(: Erythrophleum ivorense A. Chev.), a key tropical species from the Congo Basin, is widely used in structures subjected to high mechanical loads. This study investigated the intra-tree variability of its physical, mechanical, and viscoelastic properties to optimize its structural applications. Samples were collected using a double stratification: three longitudinal positions (base, mid-height, top) and three radial positions (center, middle, periphery). Axial compression, four-point static bending, and dynamic viscoelastic tests (WAVET) were conducted to assess density, compressive strength, modulus of elasticity (MOE), modulus of rupture (MOR), storage modulus (E′), loss modulus (E″), and loss factor (tan δ). LMM and Tukey’s test showed that the means differed significantly according to radial and longitudinal positions. Mechanical and viscoelastic properties improved from the center to the periphery, with maximum values in the basal peripheral zone (B-P): density (920 kg/m³), compressive strength (80 MPa), MOR (129 MPa), MOE (20,100 MPa), and E′ (640 MPa). Conversely, central zones exhibited lower stiffness but higher damping (tan δ), linked to the transition from juvenile to mature wood. These findings support a differentiated use of Tali wood: peripheral zones for structural applications, and central zones for damping-oriented uses, promoting more efficient and sustainable valorization of tropical hardwoods.
