蛙式打夯机的单边约束多体系统动力学建模与数值模拟  

Unilateral Multibody Dynamics Modeling and Simulation of Frog-hammer

作　　者：高海平[1] 王琪[1] 房杰[1] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191

出　　处：《机械工程学报》2010年第17期68-72,共5页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(10672007)

摘　　要：蛙式打夯机的建模与数值模拟问题是典型的受到多个含摩擦单边约束作用的多体系统动力学问题。通过对蛙式打夯机及其工作环境的合理假设,建立蛙式打夯机的简化多体模型。利用第一类拉格朗日方程,得到其动力学方程,它受到两个含摩擦单边约束的作用。采用冲量-速度层面上的时间步长算法以及与判断stick-slip状态转换条件等价的线性互补公式,对蛙式打夯机的整个工作过程进行数值模拟。计算结果完整地模拟了蛙式打夯机的行进过程中的stick-slip现象和周期性离地-夯击地面的过程。利用数值结果对衡量打夯机性能的两个重要参数,即蛙式打夯机行进速度和每次夯击过程中地面吸收的机械能进行计算。The modeling and numerical simulation of frog-hammer are typical questions about multibody system dynamics with frictional unilateral constraints. With rational assumptions on frog-hammer and its working environment,simplified multibody model of frog-hammer is established. Dynamics equations are derived by means of Lagrange＇s equations of first kind. They are constrained by two unilateral constraints with friction. Time-stepping impulse-velocity schemes and corresponding linear complementarity formulas,which is equivalent to the stick-slip transition conditions,are adopted to simulate the whole working process of frog-hammer. The numerical results perfectly depict the stick-slip phenomenon in advancing process and periodic lift off-ramming process. With numerical results,two important frog-hammer performance parameters,i.e.,the advancing velocity of frog-hammer and ramming energy absorbed by the ground per impact,are calculated.

关 键 词：蛙式打夯机 单边约束 多体系统 库仑摩擦 线性互补 

分 类 号：O31[理学—一般力学与力学基础] O39[理学—力学]