Failure Prediction And Dynamic Analysis Of The Contact Connection Structure

The contact connection structure is widely used in various types of mechanical structure,such as the bolted structure, the rivet connection structure, the pin connection structure and so on.For the contact exists in the connecting portion and these connecting structures are usually in aharsh working environment, the structure’s fatigue failure phenomenon often occur. In recentyears, due to the large-scale and flexibility of the complex structure, the dynamics of theconnecting part to the overall performance is even more important. In this paper, the fatigue life ofthe lug bolted structure and the dynamics of the aircraft skin and stringers riveted structure wasstudy by the EFM, and the remaining useful life of the lug bolted structure was predicted with GMmodel.The finite element model of the lug bolted structure was built, and the danger point wasfound through the stress analysis, then the impact on the axial stress by the preload and shear wasanalyzed, and the fatigue crack initiation life was calculated when the contact was considered andnot. The result shows that contact has an effect on the fatigue crack initiation life.The finite element model of the lug bolted structure containing crack was built, then therelationship between the stress intensity factor (SIF) and the contact, the depth of the crack and theratio of the semi-major to semi-minor was analyzed, and then the relationship between the crackgrowth rate and contact was analyzed, and the fatigue crack propagation life was calculated whenthe contact was considered and not. The result shows that contact has an effect on the crackgrowth rate and fatigue crack propagation life.A prognosis method of calculating the remaining useful life of the lug bolted structure wasprovided. The relationship between stress intensity factor and crack deep was predicted with GMmodel, and then crack growth rate and the remaining useful life was calculated.The finite element model of the aircraft skin and stringers riveted connection structure wasbuilt. The structure’s modal analysis was done and the transient dynamics analysis was done indifferent conditions. The result shows that the preload and contact are important to the dynamicbehavior of this structure.