Articles | Volume 9, issue 1
Mech. Sci., 9, 81–89, 2018
https://doi.org/10.5194/ms-9-81-2018
Mech. Sci., 9, 81–89, 2018
https://doi.org/10.5194/ms-9-81-2018

Research article 19 Feb 2018

Research article | 19 Feb 2018

Modelling, simulation and experiment of the spherical flexible joint stiffness

Songyu Li1, Liquan Wang1, Shaoming Yao2, Peng Jia1, Feihong Yun1, Wenxue Jin1, and Dong Lv1 Songyu Li et al.
  • 1College of Mechanical and Electronical Engineering, Harbin Engineering University, Harbin, 150001, China
  • 2AMRC with Boeing, the University of Sheffield, Sheffield, S60 5TZ, UK

Abstract. The spherical flexible joint is extensively used in engineering. It is designed to provide flexibility in rotation while bearing vertical compression load. The linear rotational stiffness of the flexible joint is formulated. The rotational stiffness of the bonded rubber layer is related to inner radius, thickness and two edge angles. FEM is used to verify the analytical solution and analyze the stiffness. The Mooney–Rivlin, Neo Hooke and Yeoh constitutive models are used in the simulation. The experiment is taken to obtain the material coefficient and validate the analytical and FEM results. The Yeoh model can reflect the deformation trend more accurately, but the error in the nearly linear district is bigger than the Mooney–Rivlin model. The Mooney–Rivlin model can fit the test result very well and the analytical solution can also be used when the rubber deformation in the flexible joint is small. The increase of Poisson's ratio of the rubber layers will enhance the vertical compression stiffness but barely have effect on the rotational stiffness.

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Short summary
The spherical flexible joint is used to connect the Tension Leg Platform to the seabed. It can provide low shear stiffness while bearing high compression force. So the research on the stiffness of flexible joint is necessary. The linear rotational stiffness of the flexible joint is formulated and FEM is used to verify the analytical solution. The increase of Poisson's ratio of the rubber layers will enhance the vertical compression stiffness but barely have effect on the rotational stiffness.