摘要：The purpose of this investigation is to determinethinning variation (the 3rd marginal strain3ε ) at metalsheet forming and determination critical points on formingmaterial. The main mechanical properties influencingforming condition is Young’s modulus – , density – E ρ ,yield stress –yσ , ultimate tensile strength –UTSσ , form-ing velocity – v , friction coefficient – μ (since we takefriction coefficient as a dependence of relative velocity wedo not account it as static and kinematic components butrather as single one). There were used a hypothesis whichstates that if thickness deformation from finite elementanalysis (FEA) coincides with experimental data, thanstress strain relation from FEA can be treated as correctstrength state of formed metal sheet part.
