Stiffness and energy loss in a junction.

This paper described the relationship between some clamped forces and the stiffness and energy loss in a junction which were estimated and identified. One end of the beam which was oscillated by use of an exciter was clamped with two specimens. On analysis, Herzian and Mindlin's theories were applied to the sphere builed up by spring back on the asperity when a load was applied to and removed from the roughness. It is considered that the large asperity differ from the small one in the sliding ratio. The hysteresis loops were classified into three patterns. As a result, the tangential stiffness and the energy loss were expressed by two equations, and the tangential stiffness was given as a function of the displacement on the contact surface. The identification used the FEM (finite element method)and simplex method. The stiffness increased and the energy loss decreased with an increase in clamped force.