API 617标准中规定,如果基础结构刚度在0~150%最大连续转速范围内大于轴承刚度的3.5倍,则在动力学计算中不需要考虑弹性基础的影响,反之则需要在动力学模型中加入弹性基础特性。目前很多实际应用的旋转机械都忽略了基础刚度的影响,这就...API 617标准中规定,如果基础结构刚度在0~150%最大连续转速范围内大于轴承刚度的3.5倍,则在动力学计算中不需要考虑弹性基础的影响,反之则需要在动力学模型中加入弹性基础特性。目前很多实际应用的旋转机械都忽略了基础刚度的影响,这就导致一些机组的临界转速预估误差较大,使得转子在运行过程中振动过大。本文通过对压缩机轴承区进行动刚度测试,从而得到压缩机基础刚度的实测数据,并以多项式传递函数的形式,将弹性基础的特性引入到转子系统中。通过对转子系统横向振动的分析,得到基础特性的影响规律。分析结果表明基础特性会影响转子的动力学分析结果。展开更多
Engineering-oriented modeling and synthesized modeling of the fin-actuator system of a missile fin are introduced, including mathematical modeling of the fin, motor and multi-stage gear reducer. The fin-actuator model...Engineering-oriented modeling and synthesized modeling of the fin-actuator system of a missile fin are introduced, including mathematical modeling of the fin, motor and multi-stage gear reducer. The fin-actuator model is verified using dynamic stiffness testing. Good agreement is achieved between the test and theoretical results. The parameter-variable analysis indicates that the inertia of the motor rotor, reduction ratio of the reducer, connection stiffness and damping between the actuator and fin shaft have significant impacts on the dynamic stiffness characteristics. In flutter analysis, test data are directly used in the frequency domain method and indirectly used in the time domain method through the updated fin-actuator model. The two methods play different roles in engineering applications but are of equal importance. The results indicate that dynamic stiffness and constant stiffness treatments may lead to completely different flutter characteristics. Attention should be paid to the design of the fin-actuator system of a missile.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 11372023 and 11402013)
文摘Engineering-oriented modeling and synthesized modeling of the fin-actuator system of a missile fin are introduced, including mathematical modeling of the fin, motor and multi-stage gear reducer. The fin-actuator model is verified using dynamic stiffness testing. Good agreement is achieved between the test and theoretical results. The parameter-variable analysis indicates that the inertia of the motor rotor, reduction ratio of the reducer, connection stiffness and damping between the actuator and fin shaft have significant impacts on the dynamic stiffness characteristics. In flutter analysis, test data are directly used in the frequency domain method and indirectly used in the time domain method through the updated fin-actuator model. The two methods play different roles in engineering applications but are of equal importance. The results indicate that dynamic stiffness and constant stiffness treatments may lead to completely different flutter characteristics. Attention should be paid to the design of the fin-actuator system of a missile.
