Effective Implementation of Elastohydrodynamic Lubrication of Rough Surfaces into Multibody Dynamics Software

Abstract

Currently, multibody dynamics simulations are moving away from issues exclusive to dynamics to more multiphysical problems. Most mechanical systems contain contact pairs that influence the dynamics of the entire mechanism, such as friction loss, wear, vibration and noise. In addition, deformation often affects the interaction between the contact bodies. If that is the case, this effect must be considered. However, a major disadvantage arises in that it leads to an increase in the number of degrees of freedom and the computational time. Often, the general-purpose multibody dynamics software does not take into account advanced phenomena, such as a lubricated contact pair. This paper can serve as a guide to implementing the elastohydrodynamic lubrication of rough surfaces into general-purpose multibody dynamics software (in this case MSC Adams), which remains challenging. In this paper, the deformation shape reconstruction of the reduced flexible bodies is described, as well as a solution to the increase in the computational speed issues thereby caused. To alleviate this burden, advanced sensitivity analysis techniques are used. In this paper, parallel computing has been employed. The proposed method leads to reasonable computational times for the multibody dynamics simulations, including elastohydrodynamic lubrication. The proposed method is applied to the multibody dynamics simulation of the piston–liner interaction of an internal combustion engine.Currently, multibody dynamics simulations are moving away from issues exclusive to dynamics to more multiphysical problems. Most mechanical systems contain contact pairs that influence the dynamics of the entire mechanism, such as friction loss, wear, vibration and noise. In addition, deformation often affects the interaction between the contact bodies. If that is the case, this effect must be considered. However, a major disadvantage arises in that it leads to an increase in the number of degrees of freedom and the computational time. Often, the general-purpose multibody dynamics software does not take into account advanced phenomena, such as a lubricated contact pair. This paper can serve as a guide to implementing the elastohydrodynamic lubrication of rough surfaces into general-purpose multibody dynamics software (in this case MSC Adams), which remains challenging. In this paper, the deformation shape reconstruction of the reduced flexible bodies is described, as well as a solution to the increase in the computational speed issues thereby caused. To alleviate this burden, advanced sensitivity analysis techniques are used. In this paper, parallel computing has been employed. The proposed method leads to reasonable computational times for the multibody dynamics simulations, including elastohydrodynamic lubrication. The proposed method is applied to the multibody dynamics simulation of the piston–liner interaction of an internal combustion engine.