Hypothesis Formulation in Multibody Dynamics: an Education Challenge. Application to Mountain Bike Dynamics

Multibody dynamics underlies modeling projects for undergraduate students at the Université catholique de Louvain (UCL, Belgium) since 1995. Being still very active in this field – about hundred students/year dealing with a MBS-based project – we are now focusing on an important aspect of this modeling activity: the statement and formulation of ”reasonable modeling hypotheses”, which represents a crucial step in any modeling process. At the beginning of the project, their rigorous formulation is indispensable to build a model according to the problem specification. At the end of the process, students are encouraged to check – a posteriori - for the validity and/or limitation of their hypotheses on the basis of their simulation results. This educational topic will be illustrated via the modeling of mountain bikes equipped with modern suspensions and for which bounce performances are analyzed. This was the project theme of the 2008-2009 academic year at UCL for undergraduate students in Mechanical engineering (3rd year).