中文摘要：

基于柔性多体系统动力学理论建立了控制棒驱动机构（CRDM）三维实体有限元离散的刚-柔耦合动力学模型,用于计算CRDM在步跃冲击载荷下的响应。模型的方程采用模态缩减方法降低变形坐标维数,可以比非线性有限元方法更为高效地计算CRDM的运动曲线、冲击载荷和应力响应。此外,模型采用三维实体有限单元离散比杆单元离散方法具有更高的计算精度,不仅能准确地计算出大范围运动结果,而且可用于分析CRDM各部件的应力分布,找出局部应力偏大的部位。

英文摘要：

Abstract： In order to calculate the dynamic response of the control rod drive mechanism （CRDM） under the stepping loads, a three-dimensional CRDM finite element model is established based on the theory of flexible multi-body dynamics, in which the coupling of rigid-body motion and elastic deformation is considered. The modal reduction method is used to reduce the number of deformation variables in the equations, so that such model is more efficient than the nonlinear finite element method in calculating the motion curve, impact load and stress response. In addition, the present model is more accurate than the conventional finite element method using the rod element. Not only the motion curve, but also the stress distribution of each component can be accurately obtained to analyze the weak position.