Previous　experimental　investigations　(Hirakata　et　al.　Int　J　Fract　145:261-271,　2007)　have　demonstrated　that　Si/Cu/SiN/Pt/C　nano-cantilever　is　delaminated　along　the　interface　between　Cu　and　Si　layers　when　subjected　to　monotonically　bending　load,　and　the　measured　load-displacement　relationship　shows　a　nonlinear　behavior.　Based　on　the　continuum　mechanics　model,　this　study　carries　out　numerical　simulations　on　the　crack　nucleation　and　propagation　along　the　Si/Cu　interface　in　order　to　clarify　the　effect　of　plasticity　on　the　fracture　behavior　of　the　ductile　nano-component.　Exponential　type　of　cohesive　zone　model　(CZM)　combined　with　finite　element　method　was　adopted　to　characterize　the　constitutive　relationship　of　the　Si/Cu　interface.　Two　sets　of　simulations　are　performed,　i.e.,　Cu　layer　obeys　either　linear　elastic　or　Ramberg-Osgood　elasto-plastic　constitutive　relation.　The　characteristic　parameters　of　interfacial　adhesion　are　extracted　through　calibration　via　experimental　results.　The　simulation　results　indicate　that　(i)　cohesive　strength　and　work　of　separation　are　the　dominating　CZM　parameters,　and　the　exponential　CZM　is　suitable　for　describing　the　interfacial　delamination　between　the　Cu　and　Si　film　layers;　(ii)　the　Cu　film　layer　in　this　nano-cantilever　more　favorably　obeys　a　linear　elastic　constitutive　relation;　(iii)　comparing　to　bulk　Cu,　nano-scale　Cu　has　a　much　higher　yield　stress　and　hardening　rate,　which　leads　to　little　plastic　deformation　of　the　nano-cantilever　specimen　during　the　entire　delamination　process.　The　numerical　predictions　are　in　good　agreement　with　the　experimental　results,　wherein　brittle　fracture　occurred　during　the　Si/Cu　interfacial　delamination.　And　the　nonlinear　load-displacement　behavior　observed　by　the　tests　may　be　due　to　the　cohesive　law　of　the　Si/Cu　interface,　instead　of　the　plastic　deformation　of　the　Cu　film　layer.