A comprehensive method for joint wear prediction in planar mechanical systems with clearances considering complex contact conditions
Tóm tắt
A comprehensive method to predict wear in planar mechanical systems with clearance joints is presented and discussed in this paper. This method consists of a system dynamic analysis and a joint wear prediction. As the size and shape of the clearance are dictated by wear and evolve with the dynamic response of the system, the contact between the journal and bearing could be conformal or non-conformal, which makes the contact conditions in clearance joints quite complicated. Therefore a modified contact force model is employed to evaluate the joint reaction force in this study. As the nonlinear stiffness coefficient is related to the physical and geometrical properties of contact bodies and varies with the deformation, this contact force model is applicable to different contact conditions between the journal and bearing. Furthermore, based on the Archard’s wear model, the amount of wear can be quantified in the joint. And the geometry is updated to reflect the evolving contact boundary. Then, the wear process and the contact force model are integrated into the motion equations of the system to perform coupled iterative analyses between system dynamic response and joint wear prediction. In addition, a slider-crank mechanism is simulated as an example to demonstrate efficiency of the proposed method and to carry out a parametric study on mechanical systems considering joint wear. The influence of clearance size and driving power are discussed and compared respectively. The index of concordance is introduced to quantify contributions of contact pressure and sliding distance to wear rate under different types of journal motion. This study could help to predict joint wear in mechanical systems with clearances and optimize mechanisms in design.
Tài liệu tham khảo
Ravn P. A Continuous analysis method for planar multi-body systems with joint clearance. Multi-body Syst Dyn, 1998, 2: 1–24
Khemili I, Romdhane L. Dynamic analysis of a flexible slider-crank mechanism with clearance. Eur J Mech A-Solid, 2008, 27: 882–898
Venanzi S, Parenti-Castelli V. A new technique for clearance influence analysis in spatial mechanisms. J Mech Design, 2005, 127: 446–455
Tian Q, Liu C, Machado M, et al. A new model for dry and lubricated cylindrical joints with clearance in spatial flexible multi-body systems. Nonlinear Dynam, 2011, 64: 25–47
Flores P, Ambrosio J, Claro J P. Dynamic analysis for planar multi-body mechanical systems with lubricated joints. Multi-body Syst Dyn, 2004, 12: 47–74
Flores P. A parametric study on the dynamic response of planar multi-body systems with multiple clearance joints. Nonlinear Dynam, 2010, 61: 633–653
Podra P, Andersson S. Simulating sliding wear with finite element method. Tribol Int, 1999, 32: 71–81
Tasora A, Prati E, Silvestri M. Experimental investigation of clearance effects in a revolute joint. In: Bassani R, Ciulli E, eds. Proceedings of 2004 AIMETA International Tribology Conference. Rome, 2004. 1–8
Mukras S. Analysis and design of planar multi-body systems with revolute joint wear. Dissertation of Doctoral Degree. Florida: University of Florida, 20009
Mukras S, Kim N H, Mauntler N A, et al. Analysis of planar multi-body systems with revolute joint wear. Wear, 2010, 268: 643–652
Mukras S, Kim N H, Mauntler N A, et al. Comparison between elastic foundation and contact force models in wear analysis of planar multi-body system. J Tribol, 2010, 132: 1–11
Li P, Chen W, Zhu A B. An improved practical model for wear prediction of revolute clearance joints in crank slider mechanisms. Sci China Tech Sci, 2013, 56: 2953–2963
Flores P. Modeling and simulation of wear in revolute clearance joints in multi-body systems. Mech Mach Theory, 2009, 44: 1211–1222
Li J L, Yan S Z, Guo F, et al. Effects of damping, friction, gravity, and flexibility on the dynamic performance of a deployable mechanism with clearance. P I Mech Eng C-J Mec, 2013, 227: 1791–1803
Liu C S, Zhang K, Yang R. The FEM analysis and approximate model for cylindrical joints with clearances. Mech Mach Theory, 2007, 42: 183–197
Bai Z F, Zhao Y. A hybrid contact force model of revolute joint with clearance for planar mechanical systems. Int J Nonlin Mech, 2013, 48: 15–36
Yan S Z, Guo P F. Kinematic accuracy analysis of flexible mechanisms with uncertain link lengths and joint clearances. P I Mech Eng C-J Mec, 2011, 225: 1973–1983
Hugnell A B J, Bjoerklund S, Andersson S. Simulation of the mild wear in a cam-follower contact with follower rotation. Wear, 1996, 199: 202–210
Dickrell D J, Dooner D B, Sawyer W G. The evolution of geometry for a wearing circular cam: Analytical and computer simulation with comparison to experiment. J Tribol, 2003, 125: 187–192
Mukras S, Kim N H, Sawyer W G, et al. Numerical integration schemes and parallel computation for wear prediction using finite element method. Wear, 2009, 266: 822–831
Flodin A, Andersson S. A simplified model for wear prediction in helical gears. Wear, 2001, 249: 285–292
Archard J F. Contact and rubbing of flat surfaces. J Appl Phys, 2004, 24: 981–988
Wu J N, Yan S Z, Xie L Y. Reliability analysis method of a solar array by using fault tree analysis and fuzzy reasoning Petri net. Acta Astronautica, 2011, 69: 960–968