Course

Flexible multibody dynamics

Using finite element models simulating flexible system dynamics

To ensure the structural integrity of many contemporary mechanical systems, machines and mechanisms, it is important to accurately predict the internal stresses and deformations of critical parts using simulation models. The Flexible Multibody Dynamics course discusses which methods are suitable for determining stresses and deformations of components that undergo arbitrarily large movements.

Mechanical analysis of structures with small deformations can be performed excellently with linear finite element models. However, linear models are not sufficient for large movements. Within Flexible Multibody Dynamics, the so-called Floating Frame Formulation offers a possibility to combine linear finite element models of individual components in a dynamic analysis of the entire system. In this way unnecessarily inefficient non-linear finite element models can be avoided.

A successful implementation of the Floating Frame Formulation allows one to determine internal stresses and deformations of components during the movement. An advantage of this is that arbitrary assumptions about the boundary conditions and quasi-static loads are not necessary. In addition, this method also offers many possibilities for the implementation of further reduction techniques to further limit the calculation time.

Result of the course

The course covers the following theoretical aspects:

• Drawing up a dynamic model of a system consisting of various rigid parts.
• Linking finite element linear models of individual parts to the dynamic analysis.
• Model reduction techniques to reduce the number of degrees of freedom of the dynamical system.
• The numerical methods to calculate the movements and occurring reaction forces of flexible multibody systems.

In the course you will work with the following components:

• Theoretical modeling of systems consisting of different rigid parts.
• Numerical implementation of coupled equations of motion and solving them numerically.
• Numerical simulation in an open source package (Python code) or Matlab (if you have a license for this yourself).

Intended for

The Flexible Multibody Dynamics course is intended for mechanics, designers and calculators who are active in machine dynamics. Elementary experience in finite element linear models and numerical programming in Python or Matlab is desirable.

Photo: Von Mises stress during motion by Jurjen Blaauw