Study On Loosening Behavior Of Bolt Connection Under Pure Bending Load

Threaded connection structure is widely used in all kinds of engineering institutions and is one of the most widely used industrial fastening methods.As an important connection component,the loosening failure of the bolt connection will seriously affect the safety and reliability of the system.With the continuous development of industry,the performance requirements of industrial structure are increasingly stringent,and the application scenarios of bolted structure are becoming more extensive.Therefore,the loosening behavior of bolts also causes more extensive research.The mechanism of bolt loosening under transverse load has been understood to some extent.It is of great practical and scientific significance to study the loosening evolution and failure process of threaded fasteners under pure bending load,so that we can have a more comprehensive understanding of the loosening mechanism of bolts,and also provide new ideas for the prevention of bolt loosening in production practice.In this paper,on the basis of the existing pure bending loading tooling,the bolt loosening experiment was carried out to study its loosening under the action of pure bending load.Under different experimental conditions,the bolt loosening experiment was carried out under pure bending load excitation.The finite element model of the experimental tool was established,and the pure bending load was loaded in ABAQUS.The decrease of the tension force caused by the change of the contact state of the thread connection was studied.The influence rules of the influence factors such as the change of the contact state in the loosening process,the position of the load and the amplitude of the displacement load were analyzed.The change rule of contact state and residual preload under cyclic loading is analyzed and the mechanism of bolt loosening in this stage is revealed.54 pictures,16 tables,56 references.