A study on the frequency response change due to slap-slip phenomenon between two plates

Abstract

Most structures are assembled by the mechanical joints (bolt joints, lap joints, riveting, etc.). Several components are joined together by joints to form a structure. Due to the joint coupling, slap-slip phenomenon (nonlinear vibration) occurs in the structures. The characteristic of the slap phenomenon is that when a component in the structures vibrates at high amplitudes, other components are brought into dynamic contact around it. Slap phenomenon causes the repeated impacts (repeated impulses). This means that the impulse excites all frequencies so that slap phenomenon transfer the vibration energy to the high frequencies. The other phenomenon is Slip phenomenon. It is a phenomenon that the vibration energy of the structure is dissipated due to the friction phenomenon occurring near the joints. Until now, the research on slap and slip phenomenon has been studied, but the slap phenomenon has been mainly studied on the point contact, and the slip phenomenon is modeled by experimental hysteresis curve when a tangential force is applied to the bolt joints. Many studies have been carried out to fit the curves obtained using the various models to obtain equivalent parameters of bolt joints. There is no study on the frequency response change on when slap and slip phenomenon are considered together on the large area in the assembled structure connected by bolt joints. In this study, the frequency response change is studied when two plates of different sizes (Base plate, Partial plate) are assembled by a bolt joint. Numerical analysis is performed by using Altair RADIOSS to model the slap-slip phenomenon. To see its effect, the response of the base plate and the equivalent mass plate are compared. Due to the slap-slip phenomenon, the overall vibration energy is lower and transferred more than the other cases. This result is considered to be useful for the low vibration design of the structure where the slap-slip is expected, and it is necessary to analyze the quantitative effects of the method and pre-loading on the actual system.