Modeling the Influence of Finite Interface Thickness in Staggered Composites Using a Continuum-Cohesive Interface Approach

Abstract Cohesive elements are fundamental in fracture mechanics, enabling accurate simulations of interfaces and offering critical insights into material behavior under diverse loading conditions. These elements employ traction-separation laws to model the transition of interfaces from an intact state to full separation, providing a detailed understanding of fracture processes. Traditional cohesive models often assume zero-thickness interfaces, a simplification that is inadequate when interface thickness, material properties, and geometry significantly influence stress distribution and deformation. To overcome these limitations, we propose the Continuum-Cohesive Interface Approach (CCIA). This framework incorporates finite interface thickness and assigns distinct mechanical responses for compressive, tensile, and shear loading conditions. By combining continuum elements to model compressive stiffness with cohesive elements for traction-separation behavior, CCIA effectively captures the mechanical response of interfaces under complex multi-loading scenarios. A comprehensive parametric analysis highlights the influence of interface properties, such as normal strength and stiffness, and geometric parameters, including brick dimensions and overlap, on structural performance. The findings identify optimal configurations to maximize load-bearing capacity, stiffness, and energy dissipation. This computational approach provides a powerful tool for designing materials with tailored mechanical properties, advancing the development of energy-absorbing and durable structures across various engineering applications.