This paper presents a comprehensive investigation into the auxetic behavior of a mechanical metamaterial inspired by a Kiri-gami structure. Through an integrated approach involving finite element analysis (FEA), and Monte Carlo (MC) simulations, the study explores the mechanical response of the metamaterial unit cell and its tessellated configurations. The study confirms the manifestation of a negative Poisson’s ratio (NPR) through detailed deformation and stress analyses under compressive loading. The auxetic response is further validated by modeling 2D tessellations in rigid dynamics, demonstrating directional expansion during axial compression and a calculated Poisson's ratio of -0.5386. Analytical models are developed to evaluate angular de-formations and Poisson’s ratio based on geometric parameters. These models are statistically validated using MC simulation, generating probability distributions of NPR under varied geometric configurations. Sensitivity analyses reveal that the side length is the most influential parameter governing both in-plane and out-of-plane auxetic responses, followed by deformation and extrusion length. Connector length has minimal impact. These findings not only reveal the auxetic nature of the design but also offer critical insights for optimizing structural performance through parameter tuning. The study provides a robust design and analysis of auxetic metamaterials with potential applications in energy ab-sorption, flexible mechanics, and impact-resistant structures.
Innovative computational biomechanics approaches are required to optimize the fractional dynamical behavior of non-small-cell lung cancer (NSCLC), which is one of the leading causes of cancer-related mortality on a global scale. This study presents a comprehensive fractional-order computational dynamical system describing the biomechanical interactions among tumor cells, cytotoxic CD8+ T lymphocytes, and dendritic cells. The model is formulated as a set of nonlinear differential equations, and the memory effect and anomalous biological processes are introduced via the complex He transform. The equilibrium and stability analyses have provided critical values- for example, a basic reproduction number that governs the persistence or elimination of the tumor. The treatment model is a hybrid system, which entails continuous immune-tumor interactions and discrete therapeutic events. Computer modeling shows that, in cases of early surgical intervention followed by periodic chemotherapy, tumor burden decreases and the immune response is boosted. The results highlight the potential of mathematical modeling to enhance our comprehension of tumor–immune–therapy dynamics in NSCLC and to guide customized treatment planning.
This research evaluates the flexural behavior of steel plate girders with crossed stiffeners under static loading. Using ABAQUS finite element software, 22 simply supported steel plate girders were modeled and analyzed up to failure. The investigation focused on the effect of several parameters on ultimate strength: stiffener inclination angle (30°, 45°, 60°, 75°), in addition to the yield strength and thickness of the stiffeners, web, and flanges. The results demonstrate a substantial enhancement in the ultimate load as the stiffener inclination angle increased from 30° to 75°, with a considerable rise from 43% to 93% observed, noting that significant improvements were most pronounced beyond 60° inclinations. Furthermore, the ultimate capacity increased by 93-95% through an elevation of yield strength, 93-99% via stiffener thickening, 93-111% with web augmentation, and 93-97% through flange thickening. The comparative performance analysis established that cross-stiffened girders demonstrate marked improvements, with the Pareto-optimal G75D configuration achieving a maximum stiffness with a 38% enhancement and an energy absorption with a 98% increase over the baseline model. This configuration achieved superior integrated performance by maximizing strength, stiffness, and energy absorption, thereby establishing a validated design methodology for enhancing stiffened plate girders in demanding long-span bridge and structural applications.
This paper presents a novel deployable mechanism for Urban Air Mobility (UAM) vehicles that supports propeller engines in flight and folds compactly for ground transport. To optimize this complex system, a rigorous Integration of Computer-Aided Design and Analysis (I-CAD-A) framework is developed in four sequential phases: 2D kinematic pre-dimensioning, detailed 3D geometric modeling, Multi-Body Dynamic (MBD) simulations to identify operational loads, and Finite Element Analysis (FEA) for structural verification. To bridge the critical data-transfer gap between dynamic MBD joint reactions and FEA structural boundaries, this study introduces and evaluates three novel load-transformation techniques: the Direct Reactions Method (DRM), the Moments Transformation Method (MTM), and the Loads Distribution Method (LDM). The proposed integrated approach yields a robust design for the foldable opening mechanism that supports propeller engines in autonomous urban air mobility vehicles, which serves as the paper’s case study. In particular, the numerical experiments demonstrate that the proposed I-CAD-A framework yields a structurally sound, high-performance opening mechanism. Specifically, the proposed optimization process increased the minimum safety factor from the critical failure state of 0.22 to the standard value of 1.50, while incurring only a marginal mass penalty of 7.77%. Beyond the specific UAM application, this research provides a general, robust workflow for developing complex, articulated mechanical systems comprising rigid and flexible bodies. This research, therefore, not only proposes a new design for a foldable opening mechanism but also offers a detailed, structured, and robust methodology for developing complex mechanical systems composed of articulated rigid-flexible bodies.
Retraction at the author's request: https://doi.org/10.22055/jacm.2025.48691.5429The authors have requested the retraction of this article following a change in their institutional requirements regarding the recognition of the publication for internal evaluation purposes. The retraction is made at the authors’ request and is unrelated to the scientific validity, academic content, ethical conduct, or integrity of the research. No concerns regarding the data, methodology, findings, or conclusions of the article have been identified. In accordance with standard scholarly publishing practice, the original article and its DOI will remain accessible as part of the permanent scholarly record, with this retraction notice clearly linked to the article.
