交变载荷下液压缸非线性动态特性的数值分析方法  

Numerical Analysis Method of Nonlinear Dynamic Characteristics About Hydraulic Cylinder Under Alternating Load

作　　者：陈鹏霏[1] 和鹏 于泰龙 贺宇新[2] CHEN Peng-fei;HE Peng;YU Tai-long;HE Yu-xin(School of Mechanical Engineering, Changchun University of Technology, Changchun, Jilin 130012;Electrical and Mechanical School, Changchun Polytechnic, Changchun, Jilin 130033)

机构地区：[1]长春工业大学机电工程学院,吉林长春130012 [2]长春职业技术学院机电学院,吉林长春130033

出　　处：《液压与气动》2020年第8期112-119,共8页Chinese Hydraulics & Pneumatics

基　　金：吉林省高等教育学会高教科研重点课题(JGJX2017C27);吉林省教育科学规划课题(GH16173);吉林省教育厅项目(JJKH20191300KJ)。

摘　　要：针对交变载荷作用下的液压缸动力学特性,进行了数值仿真分析研究。首先,阐述了液压弹簧刚度非线性变化引起的软硬弹簧现象,以及时变摩擦力随速度变化呈现出负阻尼特征的产生机理,指出二者耦合作用是造成液压缸出现非线性动态特性的根本原因;之后,采用数值方法离散时间域步长,基于Taylor展开法确定摩擦阻尼,通过迭代求解非线性微分方程,获得活塞的速度、位移等性能参数曲线;最后,通过具体算例,采用MATLAB软件对交变载荷作用下液压缸的动态特性进行数值仿真分析。仿真结果表明,所提方法与实测出现的时域波形复杂、尖峰繁多等现象相符,可以较好地模拟液压缸的非线性运动规律,能够对工程实际提供指导。Aiming at the dynamic characteristics of hydraulic cylinder under alternating load,the numerical simulation analysis is carried out.Firstly,the phenomenon of soft or hard spring caused by the nonlinear hydraulic spring stiffness and the mechanism of negative damping of time-varying friction force are described.It is pointed out that the coupling effect of the two is the fundamental reason for the nonlinear dynamic characteristics of hydraulic cylinder.Then,the time domain step length is discretized by numerical method and the friction damping is determined based on Taylor expansion.By solving the nonlinear differential equation iteratively,the performance parameters such as velocity and displacement of the piston are obtained.Finally,the dynamic characteristics of the hydraulic cylinder under alternating load are simulated and analyzed by MATLAB software in a specific example.The results show that the proposed method is consistent with the complex time-domain waveforms and various spikes,which can simulate the nonlinear motion laws of the hydraulic cylinder and provide guidance for the engineering practice.

关 键 词：液压弹簧刚度 时变摩擦力 液压缸动态特性分析 数值分析法 

分 类 号：TH137[机械工程—机械制造及自动化]