Methods and systems for numerically simulating structural behaviors of a product using explicit FEA with a mass scaling enhanced subcycling technique are disclosed. A FEA model of the product defined by a plurality of nodes and finite elements is received. A critical time step size is calculated for each finite element and then assigned to associated nodes. Elements are partitioned into N element groups with first group requiring minimum time step size Δt1 and other element groups requiring respective time step sizes (ΔtN=2N−1Δt1). In order not to resort or repartition the finite elements and still obtain a stable solution, respective proper amounts of mass scaling are applied to those elements that have become too small to maintain a stable solution in their respective element groups. A time-marching simulation using explicit FEA with the mass scaling enhanced subcycling technique is then conducted with such a FEA model.