Study on the Suppression of Free Vibration of Structures by Interconnection.

提出了通过连接件将两个或三个结构连接起来以提高结构阻尼性能的步骤和算法。在驱动过程中，使用两个互连结构的二自由度（2DOF）系统的运动方程和三个互连结构的三自由度（3DOF）系统的运动方程来显示互连框架结构的第一模态的模态方程。提出了两自由度和三自由度系统中连接元件的调谐方法，使两自由度和三自由度系统中各系统的阻尼性能达到均衡和最大。在此基础上，结合两自由度和三自由度连接单元的调谐方法，提出了使框架结构一阶模态阻尼性能均衡和最大化的框架结构连接构件的近似调谐方法，并对两自由度和三自由度连接单元的调谐方法进行了试验研究。通过有阻尼自由振动试验，得到了模型框架的固有圆频率和模态阻尼比，并与理论值进行了比较。从实验结果可以看出，所提出的调谐方法是有效的。对以下结构的互连阻尼性能的改善进行了研究和证实：双塔、三塔、两索斜拉桥、兰格桥、简支梁桥，两个三层刚架连接结构的近似调谐法精度的改进方法提出了采用第一、第二模态位移驱动的调谐方法。提出了梁式动力吸波系统的连接杆调谐方法。

Procedure and algorithm of improving the structure damping performance were proposed by interconnecting two or three structures with connecting members. In driving the procedure, modal equations of the first mode of the framed structures interconnected were shown using the equations of motion of a two-degrees-of-freedom (2DOF) system for the two structures interconnected and the equations of motion of a three-degrees-of-freedom (3DOF) system for three structures interconnected. The tuning methods of connecting elements in the above 2DOF and 3DOF systems, by which the damping performance of each system in 2DOF and 3DOF systems was equalized and maximized, were proposed. And then the approximate tuning methods of the connecting members of interconnected framed structures, by which the damping performance of the first mode of the framed structures interconnected was equalized and maximized, were proposed using the tuning methods of the connecting elements in 2DOF and 3DOF systems.Experimental investigation for tuning method of elements in 2DOF and 3DOF systems was done. The natural circular frequencies and modal damping ratios of the model frames were obtained from experiment of damped free vibration and were compared with theoretical values. It became clear from experimental results that the proposed tuning methods are effective.Improvement of damping performance due to interconnection were investigated and confirmed for the following structures : Two and three towers, two cables of cable stayed bridges, Langer bridge and simply supported girder bridge, and two rigid framed structures with three stories.Improvement method of precision of the approximate tuning method of two structures interconnected was proposed by adopting the first and second modal displacements in driving the tuning method. The tuning method of beam-type dynamic absorbing system was also proposed by using the tuning method of a connecting member.