Abstract
Impact vibration of two beams was treated as an example of the impact vibration of continuous systems that must consider vibration modes and the followings were made clear. (1) By adopting six beam modes, the theoretical result and the experimental ones about bifurcation diagram agree well each other qualitatively, and the characteristic of the diagram is a little different from that of the beam and the wall system. (2) From the viewpoint of the engineering, the transition from periodic motion to chaos is interpreted as the grazing bifurcation and its bifurcation changes a little depending on the phase of beams. (3) The tendency of the energy levels of the modes excited by the impact is similar to the case of the impact vibration of the beam and the wall.
