An elastic-plastic model for accurately predicting the riveting force and deformation of pressure riveting aluminum alloy

The riveting force is one of the key factors in controlling the quality of riveting. In this study, a prediction model for the riveting force is proposed using elastic-plastic mechanics and the exponential hardening criterion to explore the relationship between the riveting force and the riveting deformation. The prediction model divides the rivet driven head of the rivet into easy-deformation and difficult-deformation areas. By using block analysis and overall analysis and introducing height coefficients, the model can accurately predict the riveting force of rivets with diameters not greater than 4 mm and effectively define the range of values for the riveting force of rivets with diameters greater than 4 mm. Additionally, this study constructs a three-dimensional isotropic finite element model for predicting the radial and longitudinal deformation of rivets and conducts riveting tests for rivets of different specifications. The test results show that the model has a high prediction accuracy: for rivets with a diameter of 4 mm, the error between the predicted riveting force and the test results is 1.7%; for rivets with diameters of 5 mm and 6 mm, the error between the predicted maximum riveting force and the test results is 2.9% and 6.8%. Concurrently, it is verified that the prediction model can effectively control the riveting interference within the optimal range, providing a reliable basis for optimizing the actual riveting process.