The motion of dislocations, as computed by dislocation dynamics simulations, depends on theunderlying energetic model casted within a continuum approach. This model is nevertheless stilldebated due to the diculty in capturing the behavior of the atoms in the core of dislocations.Here, we investigate the influence of the corresponding material core parameters on the outcomeof dislocation dynamics simulations of the Orowan bypassing mechanism. A parametric studyfirst reveals a large dispersion of the critical Orowan stress. Within a semi empirical approach,a new predictive equation is then motivated to encompass the core parameters, and extend theoriginal formula proposed by Bacon, Kocks and Scattergood. Emphasizing the need to carefullyselecting these parameters, we finally advocate the use of the Orowan mechanism to calibratedislocation dynamics simulations.