Investigation of the stress-deformation state of a bolt-joint assembly of cold-bent thin-walled profiles

Introduction: cold-bent profiles with a segment of the concave flat wall are used for manufacturing trusses. In these trusses, the connection between the chords and the webbing is made using gusset plates attached with bolts. Due to the shape of these profiles, the bolts can only be installed in two outer rows. While the profile wall at the place of flat concavity cannot be tightly connected with the gusset plate, so the actual work of such joints is to be studied. The aim of the study is numerical and experimental research of the stress-deformation state of the attachment of a cold-bent thin-walled profile with a segment of the concave flat wall using two rows of bolts. Materials and methods: paired cold-bent profiles with a segment of the concave flat wall connected utilizing bolted gusset plate were used for full-scale tests. Computer simulation and calculation were performed using the SolidWorks software. An examination of the assembly with two rows of bolts was carried out. Results: calculations and full-scale tests of the bolted assembly showed the variation of the forces in the bolts and profiles. It is suggested to eliminate the gap between the walls of cold-bent profiles and gusset plates that allows installing an increased number of bolt rows and reducing stresses in the thin-walled profile of the joint. Conclusions: the results of the study showed that the installation of only two rows of bolts in the joint of thin-walled profiles with a segment of the concave flat wall worsens their stress-deformation state. When filling the concave segment of the wall with sheet steel pieces, it is possible to increase the number of bolt rows and reduce the number of the bolts, increasing the bearing capacity of the cold-bent thin-walled profile and the joint as a whole.