中文摘要：

用柔性多体动力学的理论分析四节臂混凝土泵车臂架系统的动态特性。把泵车的臂架模拟成柔性机器臂，采用拉格朗日方程和虚功原理建立混凝土泵车臂架系统的柔性多体动力学方程，通过对泵车臂架运动微分方程的推导和数值求解，对泵车各臂杆的运动情况进行分析。结合动力学仿真分析软件，分别建立四节臂混凝土泵车臂架的刚性模型和柔性模型，给定相同的驱动力矩对两种不同情况下的运动模型进行分析。仿真得出两种模型的变形曲线和第四节臂杆的角速度曲线，对比仿真结果表明，在研究轻质长臂杆混凝土泵车的臂架系统时，考虑各个臂杆柔性变形的影响是非常必要的，同时，研究成果也为混凝土泵车浇注自动化的研究提供了数学模型。

英文摘要：

The flexible multi-body dynamic theory is applied into the dynamic characters analysis of 4-arms concrete pump truck arms. The arms are thought as flexible ones for simulation, based on which the flexible multi-body dynamic equation for arm system is built by Lagrange equation and virtual work theory. The equation is deduced and numerically solved to analyze the movement situation of each arm. With a dynamic simulation software, a rigid model and a flexible model are both built for the arms. These two models are simulated with the same driving moment, and the deformation curves of each model and the angular velocity curve of the 4th arm are analyzed and compared. The result shows that it is necessary to consider the flexible deformation when studying the arm system of the light and long arm concrete pump truck. At the same time, the mathematic model can support the study for automatic casting.