Inertance-integrated vibration suppression for multibody systems

Abstract

In this thesis, inertance-integrated vibration suppression methods for multibody systems are developed, and applied to the example case of railway pantograph systems.
With the introduction of the inerter, inertance-integrated vibration suppression methods fundamentally extend the achievable capability of passive vibration suppression methods. However, the inerter and its applications that have been reported in the literature were restricted in a 1-dimensional (1D) environment, i.e., the implications of the rotation of inerters have not been considered. In this thesis, inerter models in a 2D or 3D environment and the application to multibody systems are developed. Specifically, the centripetal acceleration, resulting from rotation of the inerter, needs to be accounted for to find the second derivative of the inerter length, which defines the generated force. With the inerter’s model in a 2D or 3D environment, theoretical bases of inertance-integrated vibration suppression method for multibody systems are developed.
To allow inerters to be applied to the application example of pantographs, accurate and reliable pantograph multibody models are established initially. An existing pantograph model is assessed and calibrated to fit with published experimental data. While a reasonable fit to the reported response is achieved, a lack of detailed experimental data prevents further refinement. To address this and establish an accurate and reliable pantograph multibody model, a pantograph test rig is designed and constructed. Based on this test rig, a Brecknell Willis HSX pantograph is tested and modelled. A multibody model of the tested pantograph is then developed and verified using the experimentally measured data successfully.
Inertance-integrated suspension systems are investigated for both pantograph models with the objective of reducing the maximum contact force standard deviation using the proposed inertance-integrated vibration suppression method. It is found that 40% and 38% reductions of the maximum contact force standard deviation for any speed within the operation range are possible using novel suppression device configurations when compared to the existing pantographs, respectively. It has been shown that the achieved improvements in both pantograph examples are due to the fact that with the beneficial inertance-integrated suspension, the first resonance frequency of the pantographs coincides with the natural frequency of the catenary and this appears to regulate the pantograph-catenary contact force oscillation.

Date of Award	12 May 2022
Original language	English
Awarding Institution	University of Bristol
Sponsors	China Scholarship Council
Supervisor	Jason Zheng Jiang (Supervisor), John Macdonald (Supervisor) & Simon Neild (Supervisor)