A crack tip tracking algorithm for cohesive interface element analysis of fatigue delamination propagation in composite materials

作者：Kawashita Luiz F^*; Hallett Stephen R

来源：International Journal of Solids and Structures, 2012, 49(21): 2898-2913.

DOI：10.1016/j.ijsolstr.2012.03.034

• Cohesive
• Element
• Fatigue
• Delamination
• Fibre
• Composite

A novel approach is proposed for the use of cohesive elements in the analysis of delamination propagation in composite materials under high-cycle fatigue loading. The method is applicable to delamination propagation within the Paris-law regime and is suitable for the analysis of three-dimensional structures typical of aerospace applications. The major advantages of the proposed formulation are its complete independence of the cohesive zone length - which is a geometry-dependent parameter - and its relative insensitivity to mesh refinement. This is only possible via the introduction of three nonlocal algorithms, which provide (i) automated three-dimensional tracking of delamination fronts, (ii) an estimation of direction of crack propagation and (iii) accurate and mesh-insensitive integration of strain energy release rate. All calculations are updated at every increment of an explicit time-integration finite element solution, which models the envelopes of forces and displacements with an assumption of underlying constant cyclic loading. The method was implemented as a user-defined subroutine in the commercial finite element software LS-Dyna and supports the analysis of complex three-dimensional models. Results are presented for benchmark cases such as specimens with central cut plies and centrally-loaded circular plates. Accurate predictions of delamination growth rates are observed for different mesh topologies in agreement with the Paris-laws of the material.

• 出版日期2012-10-15