Why Do Multibody System Simluation - An Update

Introduction

The NAFEMS Multibody Dynamics Working Group (MBDWG) wishes to commission an update to the 2011 NAFEMS publication “Why do – Multibody System Simulation”. The purpose of the original publication was to provide a high-level overview of the MBS methodology and the benefits that can be obtained using real industrial examples.

The document is intended to replace the existing publication and include the methods and approaches that have come into common practice over the course of the last decade. The document is anticipated to be approximately 140 A5 pages in length. It is anticipated that significant portions of the current text will be retained in the updated publication.

Proposed Updates

Potential authors are encouraged to review the existing publication and identify the areas that they believe are in need of an update. The following guidance on section which are in need of an update have been proposed by the MBDWG:

Chapter 1 - Introduction

• The introduction should touch on the new relationship that have emerged such as a convergence between MBS and FE, Multiphysics, PLM, SDM, Real Time Simulation

Chapter 2 – MBD Design and Analysis Process

• 2.1 – Introduction to Virtual Prototyping The concept of the virtual twin should be introduced along with a discussion of how the virtual twin is updated throughout the product lifecycle.
• 2.2 – Basic Modelling Elements This section should be updated to introduce modern flexible MBS components.
• 2.3 – Solving Rigid-Flexible Systems The two main methods for solving systems of rigid-flexible bodies should be introduced (Monolithic and Co-simulation). The strengths and weaknesses of the different approaches should be briefly discussed.
• 2.4 – Multidisciplinary Modeling This section requires modernisation and should include a discussion of nonlinear flexible bodies.

• 2.4.1 – Integration with FE This section should receive a major update. Non-modal techniques available via nonlinear flexible bodies should be included. The limitations of these approaches should be clearly stated.
• 2.4.2 – Integration with controls and hydraulics It is suggested that this section should focus solely on control and include information about co-simulation. It is suggested that Hydraulics is broken out into a separate section which would also cover the integration with CFD.
• 2.4.3 – Integration with Physical Testing This section is likely to require a major update to describe real time simulation techniques.

Chapter 3 – The Principles Underlying MBS

• This section should be updated with a detailed description of the principles of nonlinear flexible bodies. This should include a description on how to add nodal basis representation on the modal domain using component mode synthesis.
• This chapter should cover the different methods that can be used to formulate a flexible body.
• This chapter should also include a description of the various methods that are used to couple flexible bodies with rigid elements.
• A section on the methods used to allow MBS simulations to run in real time is required.

Chapter 4 – Industrial Applications

• The example applications should be revised. It is suggested that applications are selected that cover, real time simulation capabilities, nonlinear flexible bodies, coupling with CFD.

Chapter 5 – Emerging Trends

• This section should be revised. Particular attention should be made to the merging of MBS and FE.

Suggested New Chapters

• Potential authors should consider developing a chapter on gear and transmission simulation.

Appendices

• The existing publication has appendices with links to MBS vendors and external communities. This section is now out of date and requires revision.

Format

The publication should be developed in Microsoft word format conforming to the standard NAFEMS publication template. Figures should also be provided as a separate jpg or tiff files with a minimum resolution of 300dpi with a file name in keeping with the figure number.