Abstract
This study investigates the behavior of TRIP steel composites reinforced with magnesium-partially stabilized zirconia (Mg-PSZ) particles, focusing on crack propagation, stabilization, and its impact on material performance. Using a combination of experimental techniques and cohesive zone modeling (CZM), we construct a detailed geometry from SEM images to analyze global stress-strain responses. The stress-strain curves for models with perfect bonding and varying contact strengths (300, 330, 360 MPa) reveal that while both models exhibit similar trends in the elastic region, significant differences arise in the plastic region. The damage model shows both softening and hardening behaviors due to interfacial delamination, with higher contact strengths resulting in increased stress values at the same strain. Notably, the median stress values exceed mean values in the hardening region, influenced by extreme values and underscoring the limitations of averaging in capturing overall material behavior. Further analysis of crack propagation, illustrated through incremental crack numbers and polar coordinates, indicates that unstable cracks develop before 1% strain, transitioning to stable propagation between 1% and 4% strain. This transition is attributed to the nonlinear interfacial morphologies that restrict delamination driving forces. Moreover, the unstable cracks initially dominate, leading to softening in the global stress-strain response. As crack propagation stabilizes, the material behavior shifts to hardening, reducing delamination and enhancing matrix reinforcement. Overall, this research provides comprehensive insights into the interplay between interfacial damage and material response in TRIP steel composites. Detailing the effects of crack propagation and stability highlights the importance of accurate modeling and analysis for optimizing the performance and reliability of reinforced steel composites.
