Open-Hole tensile tests on poplar veneer laminates and plywood: Applicability of the point stress criterion

This study explores the open-hole tensile strength of two types of poplar veneer laminates: a quasi-isotropic laminate [90°/45°/0°/–45°] s and a plywood laminate [90°/0°/90°/0° 1/2 ] s . The effects of hole diameter and specimen geometry on tensile strength were examined, and the Point Stress Criterion (PSC) was used to evaluate material behaviours. The results show that the stress concentration values (d 0 ) for the veneer laminates align closely with those of fibre-reinforced polymer composites, demonstrating the applicability of the PSC to wood-based laminates. While the d 0 values are similar to those observed in synthetic composites, the failure mode differs significantly. Unlike most synthetic composites, no delamination occurs near the hole or along the edges of the studied laminates. Instead, the specimens exhibit a brittle fracture mode, characterised by sudden failure without ply separation. These findings provide insights into the influence of hole effects on laminate design and suggest that the PSC can be used to optimise the performance of veneer laminates in engineering applications.