High-performance tensile testing machine

• Subject Area: Materials Science
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 454197586

The requested high-performance tensile testing machine is indispensable for the development of strength gradings for wood lamellas for the production of glued laminated timber, cross laminated timber and structural timber according to European standards. It makes it possible to correlate grading parameters such as knot size, natural frequency measurement, fiber deviation, position in the tree trunk (and similar) with tensile strengths and tensile modulus of elasticity. This knowledge can then be used to predict the strength of the above mentioned building materials. Using these strength values, engineers can then calculate load-bearing structures - the basis for a building application. Determination of the tensile strength is also essential for the so-called finger-jointing - a longitudinal joint of wood, which is used to produce timber of "endless" length. Without such tests it is not possible to work out the normative basis for the constructive use of, for example, beech, oak or birch wood from native forests.The last Federal Forest Inventory and the forecasts for the future availability of wood in Germany predict a sharp increase in the availability of hardwoods and a reduction in the availability of softwoods. The German construction industry uses almost 100% softwood for the construction of roof trusses, wooden houses, facades, bridges and roof structures of halls. The use of wood in construction is constantly increasing. The softwood resources that are no longer available cannot easily be replaced by hardwoods. Important scientific fundamentals are missing in the field of strength grading, general strength parameters of different products, bonding and long-term behaviour of the products. Last but not least, once the basic knowledge has been established, standards must be developed. All this is not possible without large scale tensile tests. With the high-performance tensile testing machine applied for, characteristic tensile strength values could be generated - independent from the few comparable machines, which can be found in Munich, Biel (Switzerland) and Graz (Austria) and which are running at full capacities.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Hochleistungszugprüfmaschine
• Instrumentation Group: 2900 Statische und quasistatische Prüfmaschinen und -anlagen
• Applicant Institution: Georg-August-Universität Göttingen
• Leader: Professor Dr. Holger Militz