Abstract
KEYWORDS – VPG (Virtual Proving Ground), Fatigue, Durability, Road, Vibration
ABSTRACT – The word “fatigue” was introduced in the 1840s to describe failures occurring from repeated stresses. Failure due to fatigue is the most common cause of mechanical failure and the cost in lives, injuries and money is large. Proper fatigue design can reduce these undesirable losses. Different fatigue methods have been developed over the years in order to solve fatigue problems (equivalent quasi-static, unitary responses, VPG using MBS, VPG using FEM). The objective of this study is to evaluate each one in order to select the best for the automotive industry (MBS and suspension components) depending on the development phase.
As a recent fatigue method, the present work shows a methodology that uses a Finite Element Model (FEM) that runs on a virtual proving ground. A whole vehicle co-simulation (Abaqus implicit/explicit) is shown which takes advantage of the best capabilities of each algorithm.
In the paper, some graphs will show the comparison of accelerations and damage between MBS method, FEM method and test on IDIADA’s Belgian Pavé at some instrumented points. The measured parameters were accelerations and stresses.
The Abaqus implicit/explicit co-simulation is very interesting, but it needs a lot of CPU resources. Even so, it is a method that has to be taken into account for future analysis.
The Virtual Proving Ground is the most accurate methodology to estimate suspension component durability and is also useful to know the component loads on the finite element model. However, it may be suitable to use more simplified methods in the earlier development phases.
A study of different CAE fatigue methods has been analyzed. The methodology used depends on the development phase. In early phases faster loops will be needed than in later phases. In that case the use of fast fatigue analysis makes sense.