Development and experimental verification of optimum design methods for dynamic absorbers for inhibiting pattern formation phenomena in contact rotating systems

以往的研究认为，模式形成现象的主要发生机制是线性时滞系统产生的不稳定振动。这些现象的许多特征已经用这一机制成功地解释了。在本研究中，进行了以下调查，以建立实用且易于使用的方法来防止图案形成现象的发生。(1)针对二自由度和三自由度系统，提出了一种基于稳定区和不稳定区边界存在条件的稳定性分析新方法。(2)利用这种新的稳定性分析方法，提出了一种抑制花纹形成现象发生的结构设计方法。抑制图案形成现象的动态吸收器优化设计的建立。(1)对于单自由度系统，通过假设使主系统失稳强度最大化的最坏条件，制定了一种不需要完全描述系统特性的最优设计方法。(2)针对多自由度系统，提出了一种针对各模态分别设计动力吸波器的方法。该方法有效地稳定了各模态，大大缩短了设计时间。通过实验系统验证了所提出的稳定性分析方法的有效性。这是一个多级辊子系统，模拟了造纸机等中使用的粘弹性辊子。实验主要针对单自由度系统进行。结果表明，不稳定振动发生的范围与采用新稳定性分析方法得到的结果相同，验证了该方法的有效性。在本研究结果的基础上，未来将对采用动态吸收器的预防方法的有效性进行验证。少

Previous studies have considered that the major occurrence mechanism of pattern formation phenomena is unstable vibrations generated in linear time delay systems. Many characteristics of these phenomena have been successfully explained using this mechanism.In this study, the following investigations were performed to establish practical and easy-to-use methods for preventing the occurrence of pattern formation phenomena.1. Development of a new stability analysis method and clarification of fundamental concepts(1) A new stability analysis method based on the existence condition for boundaries between stable and unstable regions was developed for two-and three-degree-of-freedom systems.(2) A structural design method that inhibits the occurrence of pattern formation phenomena was formulated by using this new stability analysis method.2. Establishment of optimum design for dynamic absorbers for inhibiting the pattern formation phenomena.(1) For single-degree-of-freedom systems, an optimum … More design method that does not require completely characterizing the system was formulated by assuming the worst conditions that maximize the instability intensity of the main system.(2) For multi-degree-of-freedom systems, a method involving individually designing dynamic absorbers for each mode was proposed. This method effectively stabilized all the modes and greatly reduced the design time.3. Experimental verificationAn experimental system was produced to verify the effectiveness of the proposed stability analysis method. This was a multistage roll system that models the viscoelastic roll used in paper-making machines, etc. Experiments with single-degree-of-freedom systems were mainly carried out. The results indicate that unstable vibrations occur in the same range as that of the results obtained using the new stability analysis method, verifying the effectiveness of this method. Based on the results obtained in this study, verification of the effectiveness of the prevention method using dynamic absorbers will be performed in the future. Less