Abstract: To simulate crack propagation in a high pressure pipeline, a cohesive zone model can be employed. Such a model idealizes the fracture process in solids as occurring within thin layers confined by two adjacent virtual surfaces. The loss of cohesion, and thus crack formation and extension, with in a solid may be viewed as the progressive decay of otherwise intact tension and shear stresses across the adjacent surfaces.
The introduction of an interface constitutive law, connecting tractions and displacements, provides a description for the progressive fracture in pipeline steels caused by subsequent void nucleation, growth and coalescence. Such a cohesive zone model allows for separation of interfaces between continuum elements, if some critical value of separation is reached locally, whereas the material outside deforms according to the imposed elastoplastic constitutive equations without any damage.
This paper provides a review of cohesive zone modeling for ductile fracture simulation. The basic framework and the historical developments are briefly covered, and different traction separation laws are compared. The merits and limits of this method to simulate ductile crack propagation are identified by comparing cohesive zone models with other numerical techniques that are frequently used in computational fracture mechanics.