Energy method for modelling delamination buckling in geometrically constrained systems

Delamination buckling analysis of laminates is of considerable interest to the mechanical and materials engineering sectors, as well as having wider applications in geology and civil engineering. With advances in computing power, the ability to model ever increasingly complex problems at more detailed levels becomes more of a reality. However, many of the common finite element packages, with the exception of all but the most specialized, do not perform particularly well where complex non-linear problems are dealt with. In many cases, these packages can fail to determine the full range of solutions or accurately predict the properties and geometry of the final state. This is particularly the case where large deformations and buckling of laminates are considered. Because of this, many researchers prefer to use what they perceive to be more reliable techniques, such as the symbolic computation of the underlying differential equations, rather than finite element approaches. The use of finite element packages is further frustrated by the steep learning curve and implicit restrictions imposed by using third-party software. In this paper, a finite element approach and an energy formulation method are considered and used to model the delamination buckling in a geometrically constrained system. These methods are compared with experimental results and their relative merits are discussed. In particular, the accuracy and the ability to represent the geometry of the buckled system are discussed. Both the finite element approach and the energy formulation are described in detail and the numerical results are compared.