System integrated passive damper "P-DACS" for directly controlling static & dynamic characteristics of structural component

Controlling stiffness and damping of mechanical systems and civil structures

With the advancement of mechanical systems such as machine tool, automobiles, spacecraft, and so on, reduction of undesired vibration is one of most important problem. For example, vibrations occurring in machine tools and industrial robots have an adverse effect on manufacturing performance and positioning accuracy. On the other hand, vibrations generated in automobiles deteriorate the ride comfort. Elastic vibrations of flexible spacecraft cause serious failer in its operation. Also, in building structures, fatigue and failer will occur due to earthquakes with various periods. In order to solve the vibration problem, nonconventional damping systems must be developped.

In conventional vibration damping technology, high damping material such as resin, gel, and so on, are used for reducing vibrations. In many cases, stiffness of mechanical or structural component, however, reduce when these damping materials are attached. In addition, active dampers are need to use actuators and sensors with high cost to control vibration amplitude.

In this research, we propose an passive “structure damper cell” technology named as P-DACS (Passive - Damper with Anisotropic Composit Structure) is developped.

P-DACS is the composite damper consisting of polymeric material and metalic material. By controlling anisotropity of stiffness, the damper’s vibration mode that store high straine energy in the polymetric material can be generated. Mechanical components and machine element which are integrated P-DACS can be realized by using metal additive manufacturing technology. Stiffness and damping capacity of these components are controlled by damper design. In addition, damping of multi vibration mode increases by the integrated P-DACS cells.