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Laboratory Test

The tensile test performed for the purpose of determining the yield strength of the steel used for the production of dry self-cutting al-fer connectors is available. In the wood-to-wood connections on floors, the weak element is the wood that yields with a breaking mechanism due to bearing stress. As the thickness used for the reinforcement increases, in addition to the bearing of one of the two connected wooden parts, yielding of the metal connector may occur simultaneously, with the formation of one or more plastic hinges. From in-depth studies, it was decided to use a steel for the production of the self-cutting dry connector with a yield strength of 590 Mpa.

The equations of the bearing capacity of the connection with cylindrical shank connectors are derived from simple considerations of equilibrium at the limit state, with the hypothesis of a rigid-plastic behavior for both materials. This approach, proposed for the first time by Johansen in 1949, and subsequently perfected and experimentally validated by various researchers, is today the basis of the calculation of the resistance of the connections of various technical standards both national and international.