A class of quasisteady metalforming problems under nonlocal contact and Coulomb＇s friction boundary conditions is considered with an incompressible, rigid plastic, strainrate dependent, isotropic, and kinematic harde...A class of quasisteady metalforming problems under nonlocal contact and Coulomb＇s friction boundary conditions is considered with an incompressible, rigid plastic, strainrate dependent, isotropic, and kinematic hardening material model. A coupled variational formulation is derived, the convergence of a variable stiffness parame ter method with time retardation is proved, and the existence and uniqueness results are obtained.展开更多
A class of steady-state metal-forming problems,with rigid-plastic,incompressible,strain-rate dependent material model and nonlocal Coulomb’s friction,is considered.Primal,mixed and penalty variational formulations,co...A class of steady-state metal-forming problems,with rigid-plastic,incompressible,strain-rate dependent material model and nonlocal Coulomb’s friction,is considered.Primal,mixed and penalty variational formulations,containing variational inequalities with nonlinear and nondifferentiable terms,are derived and studied.Existence,uniqueness and convergence results are obtained and shortly presented.A priori finite element error estimates are derived and an algorithm,combining the finite element and secant-modulus methods,is utilized to solve an illustrative extrusion problem.展开更多
文摘A class of quasisteady metalforming problems under nonlocal contact and Coulomb＇s friction boundary conditions is considered with an incompressible, rigid plastic, strainrate dependent, isotropic, and kinematic hardening material model. A coupled variational formulation is derived, the convergence of a variable stiffness parame ter method with time retardation is proved, and the existence and uniqueness results are obtained.
文摘A class of steady-state metal-forming problems,with rigid-plastic,incompressible,strain-rate dependent material model and nonlocal Coulomb’s friction,is considered.Primal,mixed and penalty variational formulations,containing variational inequalities with nonlinear and nondifferentiable terms,are derived and studied.Existence,uniqueness and convergence results are obtained and shortly presented.A priori finite element error estimates are derived and an algorithm,combining the finite element and secant-modulus methods,is utilized to solve an illustrative extrusion problem.
