Calculation of residual stress in ultrasonic vibration assisted grinding considering thermal-mechanical coupling: a numerical-analytical hybrid prediction approach

Ultrasonic vibration-assisted grinding (UVAG) enhances surface integrity in machined parts, especially in achieving greater compressive residual stress. Typically, the calculation of residual stresses in UVAG relies on generic finite element software that is not optimized for this purpose, suffering from cumbersome modeling and inefficient calculations. This paper introduces a numerical-analytical hybrid model tailored to predict residual stresses in UVAG. The model independently calculates mechanical and thermal stress fields using contact mechanics and finite difference methods. It employs Hertz's contact theory and Timoshenko's thermoelastic theory to establish a correlation between mechanical and thermal loads and the internal stresses in the workpiece. The residual stress field is then determined by considering the thermal-mechanical coupling effects inherent in UVAG. Experiments conducted on 12Cr2Ni4A alloy steel validate the model, with a maximum deviation of 10.5% between predicted and measured residual stresses. Further analysis shows that the presented method has a significant computational efficiency advantage over the simulation method that uses generic finite element software. The work confirms the accuracy and efficiency of the proposed model, offering a novel approach for predicting residual stress in UVAG.