Session: 03-05-01: Bioinspired materials

Paper Number: 152155

152155 - Modeling the Influence of Finite Interface Thickness in Staggered Composites Using a Continuum-Cohesive Interface Approach 

Cohesive elements are essential in fracture mechanics, enabling accurate simulations of interfaces and providing critical insights into material behavior under varying loading conditions. These elements represent material separation by defining traction-separation laws that characterize the behavior of interfaces as they transition from an intact state to full separation, offering a more detailed understanding of fracture processes. Traditional cohesive element models often simplify interfaces by assuming zero thickness, an approximation suitable for adhesive systems where interface dimensions have minimal impact on mechanical performance. However, this assumption becomes inadequate when the interface's finite thickness, material properties, and geometry significantly affect stress distribution and deformation.

To address the limitations of traditional cohesive models, and drawing inspiration from the hierarchical brick-and-mortar microstructure of nacre, we introduce the Continuum-Cohesive Interface Approach (CCIA). CCIA can assign tailored mechanical responses for different loading conditions. It models the linear elastic response of the interface under compressive loads and applies distinct traction-separation law to address fracture mechanics during tensile and shear loading. CCIA explicitly accounts for finite interface thickness and heterogeneous multi-loading behavior. It has been rigorously calibrated against experimental data under various loading conditions, including compression, tension, and shear, and is integrated into a comprehensive numerical framework to simulate the behavior of these finite-thickness interfaces in nacre-like staggered composites.

The accuracy of the numerical model was validated through three-point bending experiments on staggered structures featuring acrylic bricks joined by hook-and-hook mechanical fasteners. By incorporating the influence of complex interfacial mechanics, this work represents a significant advancement in cohesive element modeling, offering a robust framework for simulating complex structural interfaces. This model provides a valuable tool for advancing fracture mechanics and improving material design in structural engineering.

Presenting Author: Vanessa Restrepo Perez Texas A&M University

Presenting Author Biography: Dr. Vanessa Restrepo is an Assistant Professor in the Department of Mechanical Engineering at Texas A&M University. She is strongly oriented toward conducting interdisciplinary research, combining principles of solid mechanics, structural analysis, and finite element methods with biology to develop, model, and test bioinspired materials. Her current research focuses on fundamentally investigating synthetic pathways for the development of bioinspired materials and studying interlocking interfaces at the mesoscale to develop tunable heterogeneous materials.