Nonlinear structural mechanics

Fraunhofer ITWM

The department MDF is dealing with the modeling and simulation of highly deformable components and structures such as tyres, rubber bushings, air springs, cables and hoses.

Different levels of modeling are covered, ranging from computationally expensive continuum mechanical FE models to simplified macroscopic models with high performance.

It is crucial to choose the 'optimal model complexity' according to the intended application. A model must contain sufficient details to display the relevant physical effects and yet fulfill effort requirements imposed by the development process.

In this context, new mathematical methods of model reduction are developed to describe the complex behavior of a structure (e.g. a tyre) in MBS context with rather few degrees of freedom.
Commercial software like Abaqus or AmeSim is employed as well as in-house developments based on Matlab or C++.

Tyre models

Further Information

For the modeling of tyres one generally differentiates between simplified models for MBS applications and detailed FE continuum models. The latter prove advantageous concerning parameterization but exhibit a computational effort that exceeds the one of MBS models by several orders of magnitude.

The department MDF utilizes FE tyre models both for direct simulations and as a support for MBS computations.

Projects

Model reduction for Elastomer bushings

Further Information

For the inclusion of nonlinear suspension systems such as rubber bushings or air springs, MBS modeling frequently relies on surrogate formulations based on spring characteristics. This description is insufficient for the behavior of the component.Methods of model reduction are able to include complex structures under dynamic loading into a full system while maintaining its nonlinearity.

Projekte

Interactive simulation of cables and hoses

Further Information

Virtual assembly planning requires a fast and physically correct description of the behavior of cables and hoses like the ones used to operate robot arms.

In close cooperation with the "Fraunhofer-Chalmers Research Centre for Industrial Mathematics FCC", the software package IPS was developed allowing the interactive simulation of cables and hoses in real-time.

Projects