A method for modeling the dynamics of flexible bodies allowing an arbitrary gross motion, large elastic displacements and small deformations is considered. Equations of motion are derived in absolute nodal coordinates by finite element method using the known Craig-Bampton approach. The method is intended for modeling elastic solids, shells and rods included in a multibody system. Examples of practical use in modeling the dynamics of a car tire, air spring, mechanical springs are given.

Equations of motion of flexible bodies in absolute coordinates. Implementation in Universal Mechanism software. Verification. Application in well drilling dynamics, flexible tire, air spring bellows and spring models.

Modeling of pneumatic suspension of railway vehicles in Universal Mechanism software is discussed. The suspensions include air springs which can be connected with auxiliary chambers by pipelines or orifices. The models can include height control valves.

Optimization of railway wheel profile with Universal Mechanism software

The second part of the paper includes numerical tests verifying equations of motion of flexible bodies in absolute coordinates with rectangle and isosceles trapezoid finite elements. The equations are formulated in the first part of the paper. The verification is based on three types of problems: calculation of natural frequencies and modes, evaluation of buckling, and computation of large static and dynamic deflections of flexible bodies. Tests show good agreement with the theoretical results and the results obtained by other authors.