A new model for stress analysis in pin-Plate interference fit joints under tension loading

The decrease of stress amplitude is generally believed as the mechanism of fatigue life enhancement in interference fit joints under cyclic loading for each load cycle. In order to exactly estimate it, a new analytical model was presented. In this model, influences of mass, geometry, and plastic deformation are considered to modify and improve the spring model, and, moreover, the stress amplitude at the smallest crossing section is investigated. Taking these factors into account, stress amplitude decrease of various interference values can be calculated more accurately; therefore, the analytical solutions have good agreement with the finite element numerical and experimental results under different interference values and load levels. The analytical model indicates that the decrease ratio of stress amplitude is of a certain value for a specific interference value with the external load under the critical value. Furthermore, the decrease ratio of stress amplitude mainly depends on the stiffness of the pin and plate, which is mostly affected by the geometric shapes and plastic deformation ranges of the pin and plate. In addition, raising the interference value leads to larger stress amplitude reduction since the plastic deformation areas expand with the increment of interference values.