Modeling of Bolted Connection Structures Considering Non-Gaussian Surface Morphology Features and Non-Uniform Contact Pressure Distribution at the Interface

To address the non-uniform contact pressure in bolted connection interfaces, this study presents a novel contact model for bolted connection structures. Firstly, considering the impact of skewness and kurtosis on asperity distribution, a probability density function (PDF) for non-Gaussian surfaces is derived using the Johnson translator system. This PDF is then employed to extend the asperity contact model to the entire interface. Subsequently, following pressure distribution analysis, a discretization scheme is applied to divide the contact interface into multiple sub-regions. The proposed sub-region model is then incorporated into finite element analysis (FEA) to construct bolted connection structural model. Finally, experimental validation is performed on a flange structure, confirming the model’s accuracy. The results demonstrate that the proposed model achieves high precision, with an average error of only 0.65% in predicting the first four natural frequencies.