多体系统动力学中关节效应模型的研究进展

在一般的多体系统动力学研究中认为运动关节是理想运动副. 然而,实际中的运动关节不仅含有间隙与摩擦,还有间隙引起的关节元素之间的接触碰撞、局部变形和磨损. 多体系统动力学中的关节效应不仅引起了系统的振动和噪声,减小了系统的可靠性和寿命,而且损失了系统的精度和稳定性. 为此,对近十几年多体系统动力学中关节效应的研究进行了详细分析,总结了关节效应中间隙运动学模型、接触力模型与磨损模型在多体系统动力学中的建模过程. 其中,着重分析了多体系统动力学中关节磨损效应的研究进展,并对常用的Reye'shypothesis 和Archard 磨损模型进行了比较,详细地分析了Archard 磨损模型的演变形式以及主要磨损参数(接触应力,接触面积和滑移距离),特别分析了关键磨损参数接触应力的建模方法,解释了基于Winkler 弹性基础理论在求解接触应力时遇到的困难. 另外,介绍了4 种间隙运动副(转动副、移动副、圆柱副和球面副) 的运动学模型. 分析了考虑关节磨损多体系统动力学模型的一般建模方法,并以平面五杆机构为例说明了其建模过程.最后,简要地展望了多体系统动力学中关节效应模型的发展趋势以及应用前景. 

RESEARCH PROGRESS OF JOINT EFFECTS MODEL IN MULTIBODY SYSTEM DYNAMICS

It is assumed that the kinematic joints are ideal or perfect in the dynamics research of general multi-body system. However, the realistic joints include not only the clearance and friction but also contact-impact, local deformation and wear between the joint element arising from the clearance. On the one hand, the presence of clearance effect in joints causes the impact dynamic load, noise and high frequency vibration. On the other hand, the system accuracy, reliability and the service life of mechanism system will be affected due to the joint clearance. The research background of joint effects in multi-body system dynamics over the past several decades is carried on the detailed analysis. The modeling processes of joint effects that contain the kinematics model of clearance, contact force model and wear model are summarized. The advanced in joint wear effect of multi-body system dynamics is focused on specially, and the comparative analysis of two common wear model of Reye's hypothesis and Archard's wear model are carried out to illustrate their differences. The evolution form and main wear parameters consisted in the contact pressure, sliding distance and contact area of the Archard's wear model are specific developed. The modeling method of key parameter for contact pressure is analyzed specially, and it is explained that the difficulty of contact pressure is formulated by Winkler elastic foundation theory. Moreover, the kinematic models of four different style joints with clearance are briefly introduced respectively. The general modeling method of multi-body system dynamics considering joint irregular wear clearance is discussed in a flow chart way, and the planar five-bar mechanisms is taken as an example to account for modeling process of multi-body system with irregular wear clearance. Lastly, the future development trend and application prospect of joint effect model in the multi-body system dynamics are discussed respectively.