As part of the international conference "91st Annual Meeting of the International Association of Applied Mathematics and Mechanics" in Kassel (March 15-19, 2021), the Institute of Structural Analysis will present its current research results in the field of screw axis calculation of kinematic structures. The title is "Derivation of Analytical, Closed-form Formulas for the Calculations of the Instantaneous Screw Axes of Arbitrary Rigid 3D Multi-Body Systems"