STRENGTH AND STIFFNESS OF REMNANTS OF FRACTURED TIMBER

The reliability of timber becomes a major concern when the material has been stressed to fracture limit. Information on the structural integrity of the remnant is not available due to the practice of cutting and reusing undamaged timber sections. Without knowledge of the mechanical properties of the remnants, utilisation of the plank is rather doubtful. This article compares the strength and stiffness between unused wood and remnants of fractured plank. Bending tests were conducted on two tropical hardwood species, Scorodocarpus borneensis and Endospermum malaccense. Large-sized planks were bent to rupture limit by monotonie loading. Undamaged sections were distinguished visually and salvaged. Three-point bending test was conducted on the undamaged sections and modulus of elasticity as well as modulus of rupture was measured. For comparison, prior testing on unused wood was performed. Results indicate that the breakage of timber has trivial effect on the strength and stiffness of the remnants. There was no reduction in modulus of rupture. Fracture damage on timber plank demonstrated a localised effect. Visual assessment was sufficient to differentiate between clear and fractured sections.