Research of the design of a T-shaped node of cold-rolled profiles, the connection of which is made by a plate using a bolt connection

Abstract

Warehouse complexes and premises used to accommodate storage equipment, move lifting equipment and personnel require the creation of modern load-bearing structures of mezzanines and platforms. Such structures must simultaneously meet the requirements of low metal consumption, sufficient strength, stability and withstand a large number of cycles of application and removal of loads. The nodes that connect the beams of such structures are designed as hinged. They allow the rotation of the beams and do not transmit bending moments from one element to the wall of another. The work proposes the design of a connection node(joint) that consists of a corner of a special design that is rigidly fixed to the walls of the profiles using a bolted connection. The peculiarity of the node is that it is conditionally hinged and ensures the absence of transmission of bending moments between the elements of the node. This is achieved due to the design of the corner, which has the necessary and sufficient flexibility (rotational plasticity)to compensate for the rotation of the ends of the connected beams due to its operation within the limits of plastic deformations at the plasticity limit of the material. On the other hand, the strength of this corner should be such that the transfer of loads between the structural elements occurs without its destruction. Numerical modeling of the design of the conditional hinged node was performed and the values of stresses in the elements included in the node were obtained. It has been confirmed that under working loads in all elements of the joint, except for the corner, the stresses do not exceed the plastic strain limit of the materials from which they are made, equivalent plastic deformations do not exceed the limit values (5%). The corner structure operates within the limits of plastic deformations and plays the role of a conventional hinge assembly. In certain zones of the corner structure, under working loads, stresses arise that exceed the limits of plastic strain limit of the material from which it is made. The destruction of the assembly does not occur. Such studies allow us to obtain detailed information about the magnitude of the stresses in all elements of the structures and to predict their behavior in real operating conditions, which ultimately provides the opportunity to develop modern structures with low metal consumption that are capable of operating throughout the entire service life without premature failure.