Sylvatest

Timber Beam Strength Test

Sylvatest is an ultrasonic measuring device that provides an overall diagnosis of a wooden component to test its mechanical strength. This is a specific non-destructive testing tool for wooden beams.

Description

Sylvatest is an acousto-ultrasonic measuring device that provides an overall diagnosis of the wood element, based on the speed and energy absorption of the transmitted ultrasonic wave. ^{[1] [2] [3]} The result given reflects the residual health of the wood in the trunk of the tree tested or the beam measured. These are non-destructive tests. ^{[4] [5]}

The technology was developed by Professor Jean-Luc Sandoz as part of his thesis at EPFL in 1984. ^{[4] [6]}

Characterization of wood by ultrasound

Non-destructive ultrasonic testing of wood is a method used to assess its mechanical properties, particularly the modulus of elasticity in different directions. It is based on measuring the propagation velocity of sound waves through the material and the density of the wood.

Grading by ultrasound

Principle

An ultrasonic wave is emitted through a wood specimen using a transducer (sender) placed at one end. It is received by a second transducer (receiver) at the opposite end. The transit time is used to calculate the propagation velocity V of the wave through the material. This velocity is directly related to the mechanical properties of the wood.

Reused wood structural diagnostic

Fundamental Equations

The propagation velocities of ultrasonic waves in a material, such as wood, are directly related to its mechanical properties and density.

Longitudinal (VL) and radial (VR) wave speeds can be expressed as:

${\displaystyle V_{L}={\sqrt {\frac {c_{L}}{\text{density}}}}={\sqrt {\frac {E_{L}}{\text{density}}}}}$

${\displaystyle V_{R}={\sqrt {\frac {c_{R}}{\text{density}}}}={\sqrt {\frac {E_{R}}{\text{density}}}}}$

• density is the material's mass per unit volume.

These relationships are commonly used in non-destructive testing (NDT), particularly in ultrasonic transmission techniques, to assess the internal mechanical condition of wood and other materials.

Applications

Diagnostic Sylvatest grume chêne pour flèche de Notre Dame

This method is widely used for:

• assessing the quality of structural and construction timber,
• inspecting historical structures (e.g., heritage roof trusses),
• detecting internal defects such as cracks or decay,
• reuse wood structural diagnostic,
• scientific studies on the anisotropic mechanical behavior of wood.

It was notably applied in the structural assessment of the spire of Notre-Dame Cathedral in Paris, to evaluate the mechanical condition of oak beams without destructive sampling. ^[7]

The sylvatest is used in many countries (Brazil, Europe and Asia). ^{[4] [8] [9] [10] [11]}

It has been used on historic buildings such as the Entrepôts des magasins généraux in Paris, the Forbidden City in Beijing, and the beams of Notre-Dame de Paris ^{[7] [12]} or even the Château de Valère. ^[13]

It is also used to certify the quality of wood for registered designations of origin such as Bois des Alpes ^{[14] [15]} or Bois de Chatreuse. ^{[16] [17]}

Bibliography

• Research seminar: Diagnosing century-old reclaimed timber with a view to its reuse; ^[18]
• Nondestructive Techniques for Determination of Wood Mechanical Properties of Urban Trees in Madrid; ^[19]
• CMechanical strength of structural timber. Taking account of singularities when modelling mechanical behaviour. ^[20]
• Rita Bütler, Lita Patty, Renée-Claire Le Bayon et Claire Guenat, Forest Ecology and Management, vol. 242, avril 2007, p. 791–799 ^[21]
• Document de travail Interreg France-Suisse de 2019 ^[22]
• Probe-wood contact and gauge pressure with Sylvatest-Duo for precision ultrasonic measurements of wood ^[23]
• Evaluation of two acoustic methods for determining the modulus of elasticity of young hybrid larch wood (Larix x eurolepis Henry) - comparison with a standard static bending method ^[24]
• Classification of Guyanese structural timbers. Comparison of three non-destructive techniques: visual, ultrasonic and modal analysis. ^[25]
• Evaluation of modulus of elasticity of date palm sandwich panels using ultrasonic wave velocity and experimental models ^[26]

References

1. "sylvatest | interprétations | Dictionnaires et Encyclopédies sur le Akademik". Dictionnaires et Encyclopédies sur 'Academic' (in French). Retrieved 2023-10-05.
2. Technique (2013-06-05). "Tests". Le Moniteur (in French).
3. "Tares internes de bois sur pied: détection par ultrasons".
4. "CBT: le contrôle non destructif du bois au service de son usage efficient". www.leboisinternational.com (in French). 2022-06-07. Retrieved 2023-10-05.
5. "CBS-CBT: l'innovation qui marche". Fordaq. 2009-11-04. Retrieved 2023-10-05.
6. "CBS-CBT, l'expert mondial du bois enraciné en Suisse romande". Agefi.com (in French). Retrieved 2023-10-05.
7. "CBS: expertise des bois anciens et préconisations pour leur réemploi". www.leboisinternational.com (in French). 2022-07-22. Retrieved 2023-10-05.
8. "Sylvatest – IPETech" (in Brazilian Portuguese). Retrieved 2023-10-05.
9. "Sylvatest TRIO ultrasounds for wood quality assessment-Dianjiang Group Limited". www.dianjianghk.com. Retrieved 2023-10-05.
10. "Sylvatest".
11. "pemeriksaan pohon dengan sylvatest duo - DATATEMPO". www.datatempo.co. Archived from the original on 2023-05-29. Retrieved 2023-10-05.
12. Yousra Gouja (2023-06-28). "" Plus d'ingénierie, moins de matière dans la construction bois " - Cahiers Techniques du Bâtiment (CTB)". Cahiers Techniques du Bâtiment (in French).
13. "RRB'23: Château de Valère du 16 septembre 2023 à Basilique de Valère | Sortir.lenouvelliste.ch | La plateforme des événements du canton du Valais". www.lenouvelliste.ch (in French). Retrieved 2023-09-28.
14. La Commission Internationale pour la Protection des Alpes. "Bâtiment multifonctionnel en bois local". CIPRA (in French). Retrieved 2023-08-13.
15. "Un bâtiment en Bois des Alpes". www.boisdesalpes.net. Retrieved 2023-10-05.
16. "Le massif de la Chartreuse, première forêt candidate à une AOC". Le Monde.fr (in French). 2003-01-10. Retrieved 2023-10-05.
17. Bois de Chartreuse - qualification Sylvatest. "Bois de Chartreuse du bois pour construire. - ppt video online télécharger". slideplayer.fr (in French). Retrieved 2023-08-13.
18. gdelaforce (2020-01-04). "To diagnose 100-year-old timber salvaged from frameworks with a view to its re-use". Matériaux pour l'éco-conception. Retrieved 2023-10-05.
19. Virgen-Cobos, Gabriel H.; Olvera-Licona, Guadalupe; Hermoso, Eva; Esteban, Miguel (29 July 2022). "Nondestructive Techniques for Determination of Wood Mechanical Properties of Urban Trees in Madrid". Forests. 13 (9): 1381. Bibcode:2022Fore...13.1381V. doi: 10.3390/f13091381 . hdl: 10261/303528 . ISSN   1999-4907.
20. "Mechanical grading of structural timber" (PDF).
21. Bütler, Rita; Patty, Lita; Le Bayon, Renée-Claire; Guenat, Claire; Schlaepfer, Rodolphe (2007-04-30). "Log decay of Picea abies in the Swiss Jura Mountains of central Europe" . Forest Ecology and Management. 242 (2): 791–799. Bibcode:2007ForEM.242..791B. doi:10.1016/j.foreco.2007.02.017. ISSN   0378-1127.
22. "Sylvatest project - interreg France - Switzerland" (PDF). Archived from the original (PDF) on 2022-04-19. Retrieved 2023-10-05.
23. www.cabdirect.org https://www.cabdirect.org/cabdirect/welcome/?target=%2fcabdirect%2fabstract%2f20163401611 . Retrieved 2023-10-05.{{cite web}}: Missing or empty |title= (help)
24. "Evaluation of two acoustic methods for determining the modulus of elasticity of young hybrid larch wood (Larix x eurolepis Henry) - comparison with a standard static bending method" (PDF).
25. "Classification des bois de construction guyanais. Comparaison de trois techniques non destructives: visuelle, ultrasonique et analyse modale".
26. Haseli, Maryam; Layeghi, Mohammad; Zarea Hosseinabadi, Hamid (January 2020). "Evaluation of modulus of elasticity of date palm sandwich panels using ultrasonic wave velocity and experimental models" . Measurement. 149 107016. Bibcode:2020Meas..14907016H. doi:10.1016/j.measurement.2019.107016. S2CID   203076768.