Overview
ISO 13061-10:2017 - Physical and mechanical properties of wood - Test methods for small clear wood specimens - Part 10: Determination of impact bending strength - specifies a standardized pendulum impact method to determine the impact bending strength (dynamic bending resilience) of small, clear wood specimens. The standard defines apparatus, specimen size and orientation, conditioning, test procedure, calculation of results and required reporting items for reproducible laboratory measurements.
Key topics and requirements
- Specimen geometry: straight prisms with a square cross-section of 20 mm × 20 mm and 300 mm length, one face radial and the other tangential.
- Conditioning / moisture content: specimens may be tested green (≥ fibre saturation point) or conditioned to constant mass at 65 ± 5% RH and 20 ± 2 °C for dry-state testing.
- Apparatus: pendulum impact (Charpy-type) machine with energy capacity about 3–5 times the work to break the specimen and energy-measurement precision of 1 J. Hammer and support radii 15 mm; support height > 20 mm; span between support centers (240 ± 1) mm.
- Test procedure: place specimen symmetrically on supports; break by a single impact (usually tangent-face impact for tangential bending; radial bending is permitted). Record the energy absorbed and the failure mode (e.g., splintering or clean break). Splintering is defined as protruding fibers ≤ 3 mm.
- Post-test measurements: cut a 20–30 mm piece near the break for determination of moisture content and density per ISO 13061‑1 and ISO 13061‑2.
- Results and calculation: dynamic bending resilience is calculated from the energy absorbed and specimen cross-section and expressed in kJ/m² (the standard provides the calculation method). Results can be adjusted to a reference moisture content of 12% using a recognized correction procedure; report mean and standard deviation for samples.
- Reporting: test reference (ISO 13061‑10), sampling info (ISO 3129), specimen size and orientation, raw results and statistics, moisture/density data, moisture-correction method (if used), bending direction, failure mode, test date and laboratory identity.
Applications and users
- Laboratories performing wood material characterization, comparative research and quality control.
- Timber and engineered wood product manufacturers evaluating toughness and impact performance.
- Structural engineers and product designers assessing dynamic resistance for components exposed to sudden loads (e.g., flooring, rails, dowel connections).
- Standards developers and certification bodies requiring reproducible, comparable test data.
Related standards
Keywords: ISO 13061-10, impact bending strength, dynamic bending resilience, pendulum impact test, wood testing, small clear wood specimens, moisture conditioning, test method.