Numerical modeling of skin-core interfacial debonding in composite sandwich beams: a comparative study between continuous and discrete methods.

Resumo

Sandwich beams are structures made of different materials with the goal of combining high bending stiffness and low mass. Nevertheless, they are prone to failure modes, especially debonding at the material interfaces. This study focuses on comparing two numerical techniques for modeling the initiation and propagation of such failures: the Cohesive Zone Model (CZM) implemented through Finite Element Methods (FEM), and the Lattice Discrete Element Method (LDEM). The configuration examined comprises fibrous-composite outer skins and a polymeric core bonded by resin-based adhesives, providing valuable guidance on the computational modeling of characteristic failure modes and supporting more informed material and geometry selections when designing sandwich structures. The computational models were reproduced using Altair® HyperMesh and OpitStruct for the FEM implementation and a Fortran code for the LDEM approach. The comparison is carried out through the force versus displacement curve generated by each model, which may serve as a reference for future studies in the field of sandwich beam debonding numerical analysis.