ABSTRACT
Often the material relation is determined with the standard uniaxial tension test. Because of the
tension test the assumption is that it represent the failure strain in case of uniaxial tension. This stems from the fact that traditional approaches to determine Barba’s law focus on the strain state on the specimen surface, but neglect the strain and stress state in the middle of the specimen (Simonsen & Lauridsen 2000, Ehlers & Varsta 2009, Hogström et al. 2009). This issue is also highlighted by Choung (2009). On the other hand, detailed investigations of tensile specimen failure clearly show that the stress state in the middle of the specimen considerably deviates from the uniaxial tension prior to the fracture initiation (Dunand & Mohr 2010, Choung et al. 2012). This fact suggests that there is a certain length scale for which Barba’s law becomes inapplicable-it does not anymore represent the failure strain in uniaxial tension. It is the objective of this paper to determine this limiting length scale.
