Abstract
The authors have been studying a multi-mode damping device consisting of a mass supported from multiple directions by eight springs, and the mass can vibrate in multi-directions. By this configuration, the device can show multi-axial vibration damping ability, so it can be called a multi-axial dynamic vibration absorber (DVA). A theory to specify the natural frequency in the x, y, and z directions fx, fy, and fz by the supporting angle of the mass has been reported in the former studies by the authors. However, some large differences were observed between experimental and theoretical results in the past studies. These disagreements are considered due to friction between the spring and supporting frame and/or the unexpected deformation of the springs. Therefore, a supporting frame to hold the springs without guides is designed in this study. We also focus on the shape of the supporting springs, and conical springs and short-length coil springs are employed. Some multi-axial DVA using the frame or springs are developed actually, and vibration measurement tests to check the natural frequency in every direction are conducted. This paper describes those experiments and discusses the obtained results.
