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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。
Using NX Nastran, the numerical analysis of the non-supported mandrel roll with rectangular cross-section ring was carried out by modal analysis. The first six natural frequencies and mode shapes under the constraint condition of mandrel roll were obtained. Effect of Mode Shape on the Working Condition of Core Roll. The stress model of the core roll of the rolling process is simplified, and the variation of nodal displacement and stress with time under the action of three different rolling time is simulated and analyzed. At the same time, the three kinds of time-domain rolling force signals were Fourier transformed, and the influence of the frequency-domain composition of the rolling force signal on the vibration of the core roller was analyzed. The research shows that the working speed of the core roller is much lower than the critical speed of the first order, and the rolling process does not cause the resonance of the core roller. The first six natural frequency of the core roller is in the sonic range and easily lead to noise pollution. At the same time, the displacement and stress response of the core roller have no effect on the different rolling time; the frequency domain composition of the rolling force signal will not cause the resonance of the core roller.