Abstract
Usually Double Cantilever Beam (DCB) samples are tested following NACE Standard TM0177-2005 procedure. The standard establish arm displacement limits as function of steel grade.
However, the increasing interest on material characterization in mild sour media imposes testing at higher arm displacements that can produce larger plasticization zones at the crack-tip of DCB specimens. It is widely recognized that the level of plasticity can significantly affect the material fracture behavior. Therefore, It is important to study the loading conditions that cause the loss of linear elastic response in DCB samples.
In the present paper several elastic plastic and linear elastic 3D finite element models of DCB geometry have been performed. The models consider a wide range of crack lengths to half specimens height (a/h) ratios and different material properties (different YS levels). The obtained results allow to correct the fracture mechanics parameters of DCB samples due to elastic-plastic effects and to establish a criterion to determine the range of applicability of linear elastic fracture mechanics.
