A kriging model for dynamics of mechanical systems with revolute joint clearances

摘要

Over the past two decades, extensive work has been conducted on the dynamic effect ofjoint clearances in multibody mechanical systems. In contrast, little work has beendevoted to optimizing the performance of these systems. In this study, the analysis of revolutejoint clearance is formulated in terms of a Hertzian-based contact force model. Forillustration, the classical slider-crank mechanism with a revolute clearance joint at thepiston pin is presented and a simulation model is developed using the analysis/designsoftware MSC.ADAMS. The clearance is modeled as a pin-in-a-hole surface-to-surface drycontact, with an appropriate contact force model between the joint and bearing surfaces.Different simulations are performed to demonstrate the influence of the joint clearancesize and the input crank speed on the dynamic behavior of the system with the joint clearance.In the modeling and simulation of the experimental setup and in the followed parametricstudy with a slightly revised system, both the Hertzian normal contact force modeland a Coulomb-type friction force model were utilized. The kinetic coefficient of frictionwas chosen as constant throughout the study. An innovative design-of-experiment(DOE)-based method for optimizing the performance of a mechanical system with therevolute joint clearance for different ranges of design parameters is then proposed. Basedon the simulation model results from sample points, which are selected by a Latin hypercubesampling (LHS) method, a polynomial function Kriging meta-model is establishedinstead of the actual simulation model. The reason for the development and use of themeta-model is to bypass computationally intensive simulations of a computer model fordifferent design parameter values in place of a more efficient and cost-effective mathematicalmodel. Finally, numerical results obtained from two application examples withdifferent design parameters, including the joint clearance size, crank speed, and contactstiffness, are presented for the further analysis of the dynamics of the revolute clearancejoint in a mechanical system. This allows for predicting the influence of design parameterchanges, in order to minimize contact forces, accelerations, and power requirements dueto the existence of joint clearance.