中文摘要：

研究了航天器贮箱变质量流固耦合系统的动力学特性.根据虚拟质量法（VMM）,结合边界元法和有限元法构建了系统的动力学模型,建模过程中着重考虑了质量变化对系统的动态影响.通过Newmark直接积分法计算出贮箱变质量系统的振动响应.结果表明：由于系统质量减少,引起了系统振动频率的增大,并产生一个附加负阻尼.系统的振动频率的范围可以通过系统质量的范围确定.变质量引起的附加负阻尼的大小与系统的质量变化率成正比.对于系统的横向振动,质量减少引起的附加负阻尼在整个过程对系统振动的影响比较稳定,对于系统的纵向振动,质量减少引起的附加负阻尼对系统振动的影响随时间的增加而增大.

英文摘要：

Dynamic characteristics of a fluid-structure coupling system with variable mass in a tank of spacecraft were mainly investigated. Dynamic model of system was estab- lished by using boundary element method and finite element method based on virtual mass method （VMM）. The effect of variable mass on the dynamic response of the system was mainly considered. The vibration responses of the system with variable mass tank were cal- culated by using Newmark direct integration method. Results show that the decrease of the mass of system induces the increase of the vibration frequencies of the system, and generates an additional negative damping. The frequency range can be determined by the range of the mass of the system. It is derived that the additional negative damping induced by variable mass is proportional to rate of change of the mass. For lateral vibration of the system, the additional negative damping effects the vibration stably in the whole process, while for longi- tudinal vibration of the system, the influence of additional negative damping increases with time prolonged.