Enriched kinematic fields of cracked structures

Far from the crack tip process zone where non-linear phenomena take place, the mechanical behavior of a cracked medium can be analyzed within the framework of elasticity. Apart from the classical singular stress field associated with the elastic behavior, the effect of a confined process zone is decomposed over a set of (super-singular) fields. Because these fields are indexed by the exponent of their decay with distance from the crack tip, the dominant effect of non-linear mechanisms is characterized by the amplitudes of the first super-singular fields (modes I and II). This approach provides a macroscopic characterization of crack tip non-linearities and describes accurately the displacement field. As an application, the cyclic loading of a cracked elasto-plastic medium is discussed.