Abstract—Clearance in the joints of multibody mechanical systems such as linkage mechanisms and robots is a main source of vibration, and noise of the whole system, and wear of the joints themselves. This clearance is an inevitable matter and cannot be eliminated, since it allows the relative motion between joint components and make them assemblage. This paper presents an experimental verification of the obtained simulation results of a slider – crank mechanism of one clearance revolute joint. The simulation results are obtained with the aid of CAD and dynamic simulation softwares, which is an effective method of simulation multibody systems with clearance joints and have many advantages. The comparison between both simulation and experimental results shows that the simulation results are so close to the experimental ones which proves the accuracy and efficiency of this method of modeling and simulation of mechanical systems with clearance joints. Keywords—CAD and dynamic simulator softwares, Clearance joints, , Experimental results, Slider – crank mechanism. I. INTRODUCTION OINTS are one of the main components that are used for constructing and building of mechanical systems. They are used to connect two or more links and allow relative motion between them. They are modeled classically as an ideal or perfect. For instance, the journal and the bearing of a revolute joint are considered to be always concentric during the motion of the mechanism. However, there is always a gap between them which allows the journal to move freely and produces chaotic movements within the bearing boundaries during the motion of the mechanism. Hence, modeling of clearance joints becomes an important matter in order to study the clearance effect on the dynamic performance of mechanical systems, obtain simulation results for the kinematic and dynamic variables of the system closer to that of a real system, identify the vibration and noise levels resulted from certain values of clearances at the joints, or determine the maximum values of clearances at the joints to produce vibration and noise below a certain limits, etc. All of that attract the attention of many researchers to study how to model and simulate mechanical systems with clearance joints. Flores et al [1] studied the effect of the friction between the journal and the bearing wall on the response of a mechanism using a modified coulomb’s friction law. They also studied the effect of lubricated joint on the kinematic and dynamic results. F. A.F. Haroun is with Faculty of Engineering, Cairo University, Giza, 12613, Egypt (phone: +2010-089-82670; fax: +202-239-61-645; e-mail: Aharoun@eng.cu.edu.eg). S. S.M., Megahed is with Faculty of Engineering, Cairo University, Giza, 12613, Egypt (phone: +2010-065-41529; fax: +202-356-93-025; e-mail: smegahed@cu.edu.eg). They used slider-crank mechanism with only one revolute joint with clearance as a case study. Flores [2] studied the effect of wear occurring in revolute joints in which the amount of clearance is not of constant value as it changes over the whole mechanism life according to the theory of tribology. He combined this model with his previous model for revolute joint clearance, to simulate a slider–crank mechanism having only one real joint. Flores [3] investigated the dynamic response of a multibody system with multiple clearance joints. Different tests are performed to parametrically quantify the effect of the clearance size, the crank input speed, and the number of clearance joints on the dynamic performance of such a system. Liu et al [4] developed a FEM model to approximately represent cylindrical joints with clearance. They compared the FEM results with those obtained using Hertz model and Persson theory to study their limitations and constraints. Mukras et al [5] suggested a procedure to analyze a planar multibody system considering wear at its revolute joints. The used analysis was carried out by modeling multibody systems with clearance revolute joints. They combined this model with Archard's wear model used to compute the wear as a function of the evolving dynamics and tribological data. This procedure was verified by comparing the predicted wear from the theoretical model with that occurred with an experimental slider-crank mechanism with a clearance-joint between the crank and the connecting rod. Park and Kwak [6] made an optimal design formulation to reduce the effects of undesirable dynamics due to joint clearance. A slider-crank mechanism with one clearance-joint was used as a demonstrative example. Rhee and Akay [7] studied the dynamic response of a four bar mechanism with one clearance-joint. The motion of the mechanism rocker-arm pin at the ground connection was modeled using a Lagrangian approach. Zhu and Ting [8] made the uncertainty analysis of planar and spatial robots with clearance-joints. The used models are based on the probability density function which expresses the motion of the endpoint of a planar robot manipulator. Zhang and Huang [9] made a robust tolerance design for function generation mechanisms with joint clearance. Their model enables them to quantify the effect of uncertainties on the accuracy of function generation mechanism. Their model enables them to choose the optimal tolerances for individual components in order to minimize the assembly cost and satisfying the required mechanism accuracy in the same time. Dupac and Beale [10] investigate the effect of slider clearance in flexible linkage mechanism with crack. The impact at slider joint is modeled by restitution coefficient. The results pointed out that clearance and imperfect links change the dynamical behavior of the system and their effect cannot be neglected. Bai and Zhao [11] make a dynamic analysis for space robot manipulator with joint clearance. The contact force in joint clearance is modeled using nonlinear spring-damper element and the frictional force is modeled using coulomb's friction law. A two flexible link robot with A.F. Haroun, S.M. Megahed Simulation and Experimentation of Multibody Mechanical Systems with Clearance Revolute Joints J World Academy of Science, Engineering and Technology International Journal of Computer and Systems Engineering Vol:6, No:3, 2012 658 International Scholarly and Scientific Research & Innovation 6(3) 2012 scholar.waset.org/1307-6892/12918 International Science Index, Computer and Systems Engineering Vol:6, No:3, 2012 waset.org/Publication/12918