Stroitel’stvo: Nauka i Obrazovanie (Mar 2024)
Friction area size of the friction bolted connection
Abstract
Introduction. In the normative method of calculation of joints of steel elements on high-strength bolts, the main influence on the bearing capacity of the joint is the bolt tension force and the friction coefficient, while the width of the plates to be connected is not taken into account, normative documents regulate the bolt spacing. The task of determining the influence of the width of steel plates on the load-bearing capacity of the connection elements was set. For this purpose, several butt joints of plates with double-sided overlays made of hot-rolled steel grade St3sp5 according to GOST 19903–2015 were manufactured. One of the butt plates is made of different widths and is fastened with one bolt so that the exhaustion of bearing capacity occurs in this section. After that, the joint is stretched and brought to the limit state on a breaking machine.Materials and methods. 6 sets of friction joint with double-sided overlay on high-strength bolts with different width of the investigated butt plate — 50; 60; 70; 80; 90; 100 mm were made. The plates are connected by a high-strength bolt set of strength class 10.9 of size M14. The surface of the plates was sandblasted. An Instron 1000HDX tensile testing machine was used to determine the shear force.Results. The bearing capacity of joints with different widths of the plates to be joined was determined, the results obtained were compared with the calculated theoretical values of bearing capacity, the shape and size of the friction area were determined. Three specimens were brought to failure, it was revealed that failure occurs as a result of exhaustion of tensile strength of the plates, as well as plate gouging as a result of buckling of the joined elements.Conclusions. It was found that the size of the friction zone is 2.1–2.3 of the hole diameter, the bearing capacity of the joint does not depend on the width of the elements.
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