Evaluation non destructive des performances mécaniques du bois par méthodes AUS, acousto-ultrasonore

• Research unit: COST
• Project number: C97.0073

Key words (French)

METHODE NON DESTRUCTIVE; MECANIQUE DU BOIS; ACOUSTO-ULTRASONIQUE; TRIAGE

Research programs (English)

COST-Action E8 - Propriétés mécaniques du bois et des produits du bois

Short description (English)

See abstract

Partners and International Organizations (English)

A, B, CH, CZ, D, DK, E, F, FIN, H, I, IRL, N, NL, P, PL, S, Sl, UK

Abstract (English)

The use of timber as a structural material is basically related to its quality management due to its mechanical variability. In order to design performant timber structures by using an advanced reliability concept (Limit state design, Eurocode 5), timber material has to be graded in specific strength classes, based on both MoE and MoR values. The acousto-ultrasonic grading method has been developed as an upgrading of the stress wave ultrasonic technique. The basic non destructive variables are the speed of the law frequency wave, and the transmitted energy in the time domain. Based on these two technical data, MoE and MoR can be evaluated with a very good correlation. For sawn timber, MoE is evaluated with a regression coefficient of r2 = 0.7 and for MoR, r2 = 0.5. For glued laminated timber, MoE is given in a deterministic level (r2 = 0.92). Some case studies like the Hannover Expo roof supported by round columns or pedestrian bridges made of wooden poles will show the interest of high performance timber graded by AUS. The AUS method (acousto-ultrasonic) can be applied to forest management or log grading, at the planning level, project by project. Its also an efficient tool for the qualitative forest management for both natural and plantation forests.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C97.0073