Flex Joint Connector This component can be used to model ball joints, hinges and universal joints with specified rotational stiffness. It will introduce one extra element with zero length at the segment end to which it is attached, and add 6 degrees of freedom to the system model. The translation directions of freedom are suppressed by use of linear constraint equations. Note that this component cannot be used in combination with bar elements. This should be used with care at supernodes with user defined boundary conditions for rotations in Slender system to avoid singularities in the FEM solution procedure. Non-linear stiffness properties should be used with care. A smooth curve should be used to define the non-linear stiffness. Ball Joint Connector Internal Fluid