123 Separate-Identification Method of Coulomb Friction and Viscous Damping at the Supporting points

In systems with high stiffness, effect of Coulomb friction on the behavior of the dynamical system is relatively small because it is determined by the ratio to the stiffness of the system. In systems with low stiffness such as the simply supported beam in the vicinity of the buckling, Coulomb friction produces equilibrium regions around the stable and unstable steady states under the pithfork bifurcation without Coulomb friction. After the transient response, the beam can stop any states in the equilibrium region, which depend on the initial condition. Therefore, it is very important to determine amount of Coulomb friction. In this paper, we propose separate-identification method of Coulomb friction and viscous damping at the supporting points from free oscillation. In addition, we identify Coulomb friction from behavior of the beam with different initial condition.