An Experimental Study On The Nonlinear Characteristics Of The Ringed-wedge Connection Structure

The ringed-wedge connection structure was widely used for the virtues of reliable connection, convenient assemblage, small add-ons and smooth exterior. It often works under the conditions of vibrations. Under this condition, the structure may be loose, fray, etc. In order to find out the influence of the conditions on the structure, it was necessary to research about the dynamic character of the structure.The ringed-wedge connection structure was studied in this dissertation. The dynamics character was researched through the experimental method. The nonlinear character was found and described. The hereinafter were studied in this dissertation.The nonlinear character of the structure was studied by the change of the modal parameters. It was assumed that the structure was linear in a small subsection. In each subsection, the modal parameters were identified with the method of vibration experimental modal analysis when the structure was excited by different force. A rule was found that both the modal frequencies and the modal damp changed with the exciting force. This was the typical character of the nonlinear structure. The Hilbert translation method was used to detect the nonlinearity of the system. And the odds of the G-H were accumulated to describe the nonlinearity in amount. Another rule was found that the nonlinearity of the structure boosted up with the accretion of the exciting force.The response of the structure was analyzed in order to study its nonlinear character. The structure's responses to different exiting force were researched, and the result showed that the relationship between the increase of the response and the increase of the exciting force was not a linear one. The responses of the points below the ringed-wedge were compared with the corresponding points over the ringed-wedge and the force vs displacement hysteretic loops are constructed. The responses of different points to the exiting force of different frequencies, different accelerations were compared to confirm the structure's performance of transferring vibrations.At last, the dissertation was summarized and the research to be continued was prospected.