We consider singular perturbation variational problemsdepending on a small parameter ε. The right hand side is suchthat the energydoes not remain bounded as ε → 0. The asymptoticbehavior involves internallayers where most of the energy concentrates. Three examples are addressed,with limits elliptic, parabolic and hyperbolic respectively, whereas theproblems with ε > 0 are elliptic. In the parabolic and hyperboliccases, thepropagation of singularities appear as an integral property after integratingacross the layers.
