arXiv subjects

F. Javier Dominguez-Gutierrez

Publications and source records attributed to F. Javier Dominguez-Gutierrez.

3 recordsLinked to original sources

arXiv2026

Molecular Dynamics Study of Irradiation-Induced Defect and Dislocation Evolution in Strained Nickel

Molecular dynamics (MD) simulations were performed to investigate the influence of mechanical strain on irradiation-induced defect and dislocation evolution in nickel single crystals subjected to cumulative overlapping 5 keV collision cascades at 300 K. The simulations reveal that tensile strain modifies the dynamics of defect generation and recovery, promoting stress-assisted defect mobility and enhancing defect survival compared to the unstrained case. The heat spike duration and intensity decrease systematically with increasing strain, indicating faster energy dissipation and altered defect recombination behavior under applied stress. Analysis of the dislocation structure shows that Shockley-type partial dislocations dominate the microstructural response, while Hirth and other dislocation types remain comparatively minor. Both the total and Shockley dislocation densities reach a saturation value of $~10^{16}m^{-2}$ , marking the establishment of a steady-state microstructure governed by the balance between dislocation accumulation and recovery. The evolution of the total dislocation density with strain is successfully described by the Kocks-Mecking model, demonstrating its applicability to strain-dependent irradiation effects in metallic systems

cond-mat.mtrl-sci↗

arXiv2026

Transformation-mediated twinning governs plasticity in body-centered cubic nanocrystals under extreme loading

Plasticity in body-centered cubic (BCC) nanocrystals is often associated with twin nucleation phenomena under extreme loading conditions. Here, we reveal unconventional twinning pathways that operate at the intersection of crystal plasticity and structural phase transitions. We show that the classical shear-driven twinning mode becomes progressively suppressed with increasing pressure, giving rise to transformation-mediated twinning pathways involving transient HCP or FCC phases. In BCC Fe, Ta, and Nb nanocrystals of moderate elastic stiffness, plasticity is consistently initiated by an elastic instability that triggers a dual-shuffle process mediated by stable or metastable hexagonal closed-packed (HCP) phases. This pathway operates independently of the characteristic {112} twin boundary planes and is driven by compression, challenging the conceptual paradigm for metal plasticity in which plastic deformation arises from shear stresses resolved on specific planes. By contrast, in the archetypal elastically stiffer BCC Mo and W nanocrystals, plastic deformation proceeds via two alternative twinning pathways associated with shear-driven elastic instabilities mediated by highly-distorted face-centered cubic (FCC) phases. Comprehensive analyses of the energy landscapes to the competing nanoscale twinning modes provide mechanistic insight into their activation, establishing a unified framework for transformation-mediated twinning in BCC nanocrystals across a broad range of loading conditions.

cond-mat.mtrl-sci↗

arXiv2025

A Data-Driven Machine Learning Approach for Predicting Axial Load Capacity in Steel Storage Rack Columns

In this study, we present a machine learning (ML) framework to predict the axial load-bearing capacity, (kN), of cold-formed steel structural members. The methodology emphasizes robust model selection and interpretability, addressing the limitations of traditional analytical approaches in capturing the nonlinearities and geometrical complexities inherent to buckling behavior. The dataset, comprising key geometric and mechanical parameters of steel columns, was curated with appropriate pre-processing steps including removal of non-informative identifiers and imputation of missing values. A comprehensive suite of regression algorithms, ranging from linear models to kernel-based regressors and ensemble tree methods was evaluated. Among these, Gradient Boosting Regression exhibited superior predictive performance across multiple metrics, including the coefficient of determination (R2), root mean squared error (RMSE), and mean absolute error (MAE), and was consequently selected as the final model. Model interpretability was addressed using SHapley Additive exPlanations (SHAP), enabling insight into the relative importance and interaction of input features influencing the predicted axial capacity. To facilitate practical deployment, the model was integrated into an interactive, Python-based web interface via Streamlit. This tool allows end-users-such as structural engineers and designers, to input design parameters manually or through CSV upload, and to obtain real-time predictions of axial load capacity without the need for programming expertise. Applied to the context of steel storage rack columns, the framework demonstrates how data-driven tools can enhance design safety, streamline validation workflows, and inform decision-making in structural applications where buckling is a critical failure mode

cs.LG↗