Thermal-structure interactions on the nonlinear behavior of the heavy-load mechanical press with multiple clearance-induced joints

The thermal elastohydrodynamic (TEHD) effect contributes significantly to the improvement of dynamic behavior of mechanical presses, especially under the complex conditions of high speed, heavy load, and high temperature. In this work, a novel mixed-TEHD model and the numerical algorithm for the multiphysics problem are proposed to predict the nonlinear behavior of the mechanical press considering multiple clearance-induced joints. The propounded lubrication principle includes the thermal effects caused by contact event and the influence of TEHD on the clearance dimension under complex lubrication conditions. The equivalent nodal force method is adapted as the unified treatment of elastic and thermal deformation in the clearance joints. With the introduction of non-conservative forces, the system’s dynamic model is formulated and solved by the Lagrange approach and Newmark- $\beta$ $\beta $ integration algorithm, respectively. Numerical simulations are performed considering different fluid viscosities and crank speeds to investigate the nonlinear behavior of the mechanical press under various lubrication conditions. The results demonstrate the significance of frictional contact on the bearing thermal characteristics. Compared to the elastic deformation effect of transmission components, the variation of system position accuracy is primarily governed by the dynamics of mixed-lubricated joints. Furthermore, experimental studies are performed to validate the numerical findings.