A unified multifield formulation in nonlocal damage

The focus is on isotropic damaging materials where damage is driven by the nonlocal equivalent strain. The nonlocal equivalent strain definition is inserted into the work function by a Lagrangian multiplier. This Lagrangian formulation depends on: displacement, nonlocal equivalent strain and Lagrangian multiplier, and provides a variational basis supporting multifield formulations of both integral and implicit gradient type. Finite element results are presented for some representative one- and two-dimensional examples