Joining of wooden structures using insert threade steel washers

Introduction. Wood, being an affordable and renewable material characterized by high strength characteristics, is used in construction for both residential and non-residential buildings, as well as various structures. The strength and durability of buildings based on wooden structures largely depend on the strength and reliability of joints between wooden elements. At present, various types of nodal joints used in wooden structures all exhibit certain advantages and disadvantages, calling for an improvement and development of new types of joints having high strength and manufacturability.

Aim. In this work, the behavior of an improved joint of wooden structures using insert steel washers was investigated, along with the development of their manufacturing technology and methodology for studying.

Materials and methods. The investigation of the joint involves manufacturing a series of samples and conducting an experiment in order to determine the load to failure and ultimate strain.

Results. The manufacturing method of a joint and the experimental procedure were developed; values of load to failure and deformation were determined experimentally, with the deformation curves being plotted. It was revealed that the threaded connection of an insert steel washer and a rod leads to a decrease in the bearing capacity of the joint due to the thrust occurring in the adhesive line. In addition, it was established that the parameters of the steel washers affect the joint behavior.

Conclusion. Experimental studies of the joint showed that the threaded connection between the rod and the insert steel washers fails to increase the bearing capacity and stiffness of the joint due to the early failure of an adhesive line and the separation of the washers from a wooden element. However, using additional joints that accept the thrust in the connection can solve this problem. It is necessary to conduct additional research in order to assess the feasibility of using such a connection.

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