The effect of the lubricated revolute joint parameters and hydrodynamic force models on the dynamic response of planar multibody systems

Abstract

In this work a comprehensive methodology for dynamic modeling and analysis of planar multibody systems with lubricated revolute joints is presented. In general, this type of mechanical systems includes journal-bearings in which the load varies in both magnitude and direction. The fundamental issues associated with the theory of lubrication for dynamically loaded journal-bearings are revisited that allow for the evaluation of the Reynolds' equation for dynamic regime. This approach permits the derivation of the suitable hydrodynamic force laws that are embedded into the dynamics of multibody systems formulation. In this work, three different hydrodynamic force models are considered, namely the Pinkus and Sternlicht approach for long journalbearings and the Frêne et al. models for both long and short journal-bearings. Results for a planar slider-crank mechanism with a lubricated revolute joint between the connecting-rod and slider are presented and utilized to discuss the assumptions and procedures adopted throughout the present study. Different test scenarios are taken into account with the purpose of performing a comparative study for quantifying the influence of the clearance size, lubricant viscosity, input crank speed and hydrodynamic force model on the dynamic response of multibody systems with lubricated revolute joints. From the global results obtained from computational simulations, it can be concluded that the clearance size, the lubricant viscosity and the operating conditions play a key role in predicting the dynamic behavior of multibody systems.

A review of friction models in interacting joints for durability design

“…Modelling and simulation of multibody dynamics with joint clearances is relatively new area of research [96]. Three reviews are identified from literature namely Haines [101]-unlubricated revolute joints (1979), Flores (2010) [21] and Machado et al-compliant contact force models (2012) [102]. The problem of multibody impact with friction was first analysed by Routh in 1891 [100].…”

“…In addition, the problem of energy dissipation without violating the energy conservation condition is critical since even for low energy impacts, energy is transformed into sound and mechanical vibrations, as a function of the coefficient of restitution whose definition is subjective. The coefficient of restitution, which is representative of energy dissipation, is dependent on factors such as geometry of the contacting surfaces, pre-impact velocity, local material properties, duration of contact, temperature and friction [102]. Machado et al [102] and Flores et al [99,102] have highlighted the importance of choosing the appropriate model for the mechanism.…”

“…The coefficient of restitution, which is representative of energy dissipation, is dependent on factors such as geometry of the contacting surfaces, pre-impact velocity, local material properties, duration of contact, temperature and friction [102]. Machado et al [102] and Flores et al [99,102] have highlighted the importance of choosing the appropriate model for the mechanism. The Gonthier model [26] and Flores models are suitable for moderate to low coefficients of restitution.…”

“…For rigid link multibody mechanics simulation SimMechanics 1 st or 2 nd generation [53,145] packages can be used. For joints with clearance packages like ADAMS [25,146,147], COMPAMM, NEWEUL, DAP3D [148], MUBODYNA [102], RAPID and PARASOLIDS have been used [25] for interference detection. The problem can be formulated by using programming languages such as C/C++, Python or MATLAB m-code, depending on the intended application.…”

A numerical coupling model for a multibody system with multiple lubricated clearance joints

“…Daniel et al [13] proposed a model to analyze the dynamics performance of a slider-crank mechanism with lubricated clearance joint. Machado et al [14] studied the effect of the lubricated revolute joint parameters and hydrodynamic force models on the dynamic response of planar multibody systems. Zhao et al [15,16] established a dynamics model of the piston-connecting rod-crank system in a framework of the multibody mechanical system with lubricated joint.…”