| description abstract | This paper presents an experimental investigation on the normal dynamic characteristics of several machined joint surfaces, i.e., the varying principle of the normal dynamic stiffness and damping with exciting frequency, relative displacement and static pre-load under different joint conditions, including joint materials, mediums, machining methods and surface roughness, etc.. The joint parameters are extracted from experimental data by establishing the theoretical model of the joint surfaces, and the mechanism is analyzed qualitatively. The studied results show that, in the test range of this paper, the stiffness and damping coefficient of the joint surfaces increase with the static pre-load; the stiffness for a dry joint is independent of the exciting frequency, while the damping coefficients for both a dry and an oiled joint decrease with the exciting frequency; little relative displacement has no marked effect on the dynamic characteristics. The amount of influence of exciting frequency and static pressure is related to the joint conditions. [S0739-3717(00)00804-7] | |