The Modengy Test Center holds tribotechnical trials to detect torsion torque and pre-tightening forces of the threaded fasteners, friction coefficient in the thread, friction coefficient on the bolt or nut supporting surface, general friction coefficient, and twist coefficient.
Friction in the threaded connections affects significantly the process of assembly and operational reliability of the threaded fasteners. To study the friction processes between the turns of a nut and a bolt (stud) for the purpose of reaching optimal tightening in the connection, the test bench certified to meet the GOST ISO 16047-2015 requirements has been installed at the Modengy Test Center.
It is equipped with the sensors for force, torque, and movement, has the automatic control and data-collection system.
The new test bench enables to hold deeper study of the friction processes in the threaded fasteners.
The uniqueness of this test bench is in its capacity to measure not only general friction coefficient but also separately friction coefficient in the thread, and on the bolt or nut supporting surface.
Due to obtaining these data, it appears possibility to calculate with high accuracy tightening torque of the threaded fasteners for especially critical structures according to many Russian and foreign standards, for example, such as ASME-PCC-1 that recommend to carry out calculations taking into account friction coefficients of two kinds.
It is possible now to diagram and analyze in the real time mode the graphs of Ктр dependency from tightening, examine in dynamics the impact that lubricating materials and various coatings have upon tribological characteristics of the threaded connection.
Fig. The graphs of testing the fastening elements: force, torsion torque, and k-factor
The process of tightening the threaded connections on the bolted connection test bench is automated, and due to this, uniform tightening without errors is provided which is not available at the test benches with manual bolt tightening.
Holding the tests on this test bench enables to detect with high accuracy performances of the fasteners that are required for their reliable operating under set conditions. Due to this, it is possible to provide standard operating for the threaded connections in various fields of production such as oil and gas industry, energy, buildings and facilities construction, and others.