中文摘要：

利用NX Nastran对轧制矩形截面环件所用的端面无支撑芯辊进行了模态分析数值计算,得到了芯辊约束工况下的前6阶固有频率和模态振型,详细分析了各阶模态振型对芯辊工作状态的影响。简化轧制过程芯辊的受力模型,模拟分析芯辊在3种不同轧制时间作用下的节点位移与应力随时间的变化规律。同时对3种时域轧制力信号进行傅里叶变换,分析轧制力信号的频域组成对芯辊振动的影响。研究表明：芯辊的工作转速远低于其1阶临界转速,轧制过程不会引起芯辊的共振;芯辊的前6阶固有频率处于声波范围内,易造成噪声污染;轧制力相同时,不同轧制时间对芯辊的位移与应力响应无影响;轧制力信号的频域组成不会引起芯辊的共振。

英文摘要：

For rolling rectangle section ring, its modal analysis about the end-face unsupported mandrel was carried out by NX Nastran, and natural frequencies and modal vibration shapes of the first six orders were obtained under the constraint condition of the mandrel. Then, the influence of each mode on the working state of the mandrel was analyzed in detail. Furthermore, the force model of the mandrel was simplified in the ring rolling process, and the changes of the mandrel node displacement and stress with time under three kinds of dif- ferent roiling times were simulated and analyzed. At the same time, rolling force signals from three kinds of time domain were transformed by Fourier transform, and the influence of the frequency domain of the roiling force signals on the mandrel vibration was analyzed. The re- sults show that the working speed of the mandrel is much lower than the first order critical speed, and it can not cause the resonance of the mandrel. The first six-order natural frequencies of the mandrel are in the range of sound wave, which is easy to cause the noise pollution. Under the same roiling force, different rolling periods have few influences on the displacement and stress response of mandrel. The frequency domain components of the rolling force signals can not cause the resonance of the mandrel.