The particle size of TiO2 anodes is commonly believed to have a negative impact on their mechanical properties. As submicron-sized TiO2 exhibits low surface energy, which reduces yield strength and leads to mechanical fracture during the two-phase lithium storage mechanism, it is excluded from traditional nonaqueous lithium-ion batteries. In this study, we discovered that TiO2 demonstrates an independent size effect in an aqueous environment, mitigating the mechanical fracture associated with submicron-sized TiO2. Our studies reveal that water molecules strongly interact with submicron TiO2 materials, increasing the surface energy in aqueous electrolytes in a unique manner. This enhancement makes submicron TiO2 more resilient during the lithiation and de-lithiation reactions. Additionally, the transition from nano to submicron TiO2 facilitates the inhibition of hydrogen evolution reactions (HER) in aqueous batteries and enhances the performance of electrode coatings. Consequently, submicron TiO2 exhibits superior electrochemical performance in aqueous batteries, with an Ah-level pouch battery achieving an energy density of 66Wh kg-1 (217Wh L-1) and demonstrating excellent cycling stability of over 1200 cycles. Our work has successfully addressed the size limitations of the TiO2 anodes, offering an innovative perspective on micro-sized electrode materials previously considered unsuitable for battery use.

Influence of groove configuration on melting behavior and fracture mechanism in laser-welded aluminum‑copper hairpin joints

Molecular dynamics investigation of the microscopic deformation and fracture mechanisms in C-S-H

Enhancement mechanism of hard rock fracture and fragmentation by conical pick under coupled dynamic-static loading: Insights from impact indentation experiments

Temperature-dependent toughening of carbon/epoxy composites using rubbery NBR/PCL nanofibers: Mode I fracture and damage mechanisms

Exploring the mechanical behaviors and fracture mechanisms of Sn-0.3Ag-0.7Cu solder alloy across a wide temperature range

Effect of geometrical features of pores on the mechanical properties and fracture of ceramic materials

Experimental and theoretical investigations on the mechanical behaviors and fracture mechanism of hollow cylindrical granite under cyclic thermal shock

Mechanical properties and fracture of Net C18: molecular dynamics study and analytical model

Tailoring the fracture toughness of fluorite-type rare-earth tantalates: From atomic scale fracture mechanism to bond-mediated toughening design

Fracture mechanisms of filling layer self-compacting concrete before and after polymer repair in CRTS-III: Insights from the perspective of AE and DIC

Study on the creep fracture mechanism of the Mg-Al-Zn extrusion plate during creep forming

Optimization of Pelton turbines start-up considering fatigue damage via a fracture mechanics model

Micro-macro fracture mechanism of progressive failure with ice strengthening effect in frozen concrete of cold region tunnels

Abstract - The increasing demand for lightweight, sustainable, and high-performance materials has accelerated the development of natural fiber–reinforced composites. This study investigates the mechanical behaviour and performance evaluation of kenaf–sisal hybrid composite materials fabricated using epoxy resin as the matrix. Kenaf fibers contribute high tensile strength, while sisal fibers enhance toughness and durability, resulting in a balanced hybrid composite system. The composites were fabricated through the hand lay-up technique followed by controlled compression and curing to achieve uniform thickness and improved fiber–matrix bonding. Mechanical characterization was carried out using tensile, flexural, and impact tests in accordance with ASTM standards to evaluate strength, stiffness, and energy absorption capability. In addition, scanning electron microscopy (SEM) was employed to examine fiber distribution, interfacial bonding, and fracture mechanisms. The results demonstrate that the kenaf–sisal hybrid composite exhibits improved mechanical performance compared to single-fiber composites, with enhanced load-bearing capacity and impact resistance. SEM observations confirmed effective resin impregnation and strong fiber–matrix adhesion, contributing to improved mechanical behaviour. The developed hybrid composite offers a lightweight, eco-friendly, and cost-effective alternative to conventional synthetic composites, making it suitable for applications such as automotive interior components and structural panels. Key Words: Kenaf fiber; Sisal fiber; Hybrid composite; Natural fiber reinforced polymer; Mechanical behaviour; Tensile strength; Flexural strength; Impact resistance; Epoxy matrix; SEM analysis; Sustainable materials; Automotive applications

Purpose: This study aimed to examine 13-year changes in the injury mechanisms of orbital blowout fractures (OBFs) in Korea and to determine how those changes influenced preoperative ocular motility deficits, while also assessing whether apparent intercenter differences persisted after covariate adjustment.Methods: A retrospective cohort was assembled from two level I trauma centers: a historical 2011 series from Inje University Sanggye Paik Hospital (n=150) and a pooled 2019–2023 series from Pusan National University Hospital (n=50). Eligibility required computed tomography–confirmed medial and/or inferior wall fracture with an intact orbital rim; patients with rim involvement or penetrating ocular trauma were excluded. Injury mechanism, fracture site, and diplopia and/or extraocular movement (EOM) limitation at presentation were abstracted from electronic medical records. Categorical comparisons used the chi-square test, and trends across calendar years were assessed using logistic regression (with year as a continuous predictor). Multivariable logistic modeling estimated adjusted odds ratios (aORs) for preoperative ocular motility deficit according to age, sex, mechanism, fracture site, calendar year, and center, with robust clustering.Results: Interpersonal violence decreased from 34.7% of OBFs in 2011 to 14.0% in 2019–2023, representing an 11% annual decline (OR, 0.89; 95% confidence interval [CI], 0.81–0.97, P=0.007). Preoperative diplopia or EOM limitation was observed in 23 of 200 patients (11.5%): 14% in 2011 versus 4% in 2019–2023. Independent predictors of EOM limitation were interpersonal violence (aOR 3.84; 95% CI, 1.38–10.65; P=0.010) and male sex (aOR, 4.78; 95% CI, 1.49–15.49; P=0.009). Age showed a protective trend (aOR, 0.75 per decade; P=0.064); fracture extent and center were not significant after adjustment. Calendar year showed a borderline inverse association (aOR, 0.86; P=0.061), indicating a 14% annual reduction in presentation-time deficit.Conclusions: Between 2011 and 2023, the Korean OBF landscape shifted from violent assault to accidental mechanisms, accompanied by a marked decline in preoperative ocular motility impairment. Assault mechanism and male sex remain strong risk indicators, while center-based differences appear largely explained by temporal composition. Public health efforts that reduce violence may therefore translate directly into better functional status at initial presentation.

The determination of double-K parameters of concrete components is typically carried out through experimental and analytical methods within the framework of Linear Elastic Fracture Mechanics (LEFM). Testing large-scale concrete components with arbitrary geometry presents significant challenges. These challenges also affect the evaluation of double-K fracture parameters. To address this problem, this paper proposes an alternative numerical approach. The method consists of two main steps and is designed to determine the double-K parameters for large-scale concrete components. Based on known physical properties obtained through material property testing, the numerical results demonstrate good agreement with both analytical solutions and experimental data. In this approach, a solution-based crack propagation path is obtained using an XFEM-cohesive zone model (CZM) analysis. The critical crack opening displacement (w crit ) is employed to discretize the physical crack from the fracture process zone, while simultaneously filtering out the nodes participating crack face regeneration. The resulting physical crack model is then reinserted into the original model to perform a static XFEM crack analysis, yielding the fracture toughness curve and double-K parameters. Fracture energy and specimen thickness are identified as factors influencing w crit . Three-Point-Bending (TPB), Compact-Tension (CT), and semi-circular bending (SCB) specimens are employed to validate the accuracy of the proposed approach and investigate the characteristics of w crit . A tension-shear benchmark test specimen is employed to demonstrate the robustness and functionality of originally developed crack regeneration technique. The proposed method offers an effective approach to determine the double-K parameters and evaluate the stress intensity factors (SIFs) of arbitrarily shaped cracks. All source code is available upon request by contacting the corresponding author.

Fractography investigations may unveil the pathway behind the failure by examining the fracture surfaces, and it is a subject that requires careful consideration, particularly in aircraft structures. Fractography can identify crack initiation sites, the direction of crack growth, any associated defect in the microstructure, the environmental effect on fracture, and the type of stress within the material. Proper investigations are needed to identify the origin of failure, the direction of crack propagation, and the related fracture mechanism. This is achieved by assessing the marks on the fracture surface under the microscope. Most of the failures are the result of multiple influences and are rarely single in metallic alloys. Fatigue striations are the most prevalent indicator on the fractured surface of ductile metal alloys in the Paris region of the crack growth curve. In this study, failure analysis is performed after performing crack growth tests for different microstructures in AISI 4340 steels, especially in the near threshold region, and root causes of failure are compared for each case. Crack propagation and morphological changes up to fracture have been observed in AISI 4340 steel. Under SEM and stereomicroscope examination, each stage of crack propagation is detailed with failure analysis.

The accurate prediction of crack initiation and propagation is essential for assessing the structural integrity of mechanically joined components and other complex assemblies. To overcome the limitations of existing finite element tools, a modular Python framework has been developed to automate three-dimensional crack growth simulations. The program combines geometric reconstruction, adaptive remeshing, and the numerical evaluation of fracture mechanics parameters within a single, fully automated workflow. The framework builds on open-source components and remains solver-independent, enabling straightforward integration with commercial or research finite element codes. A dedicated sequence of modules performs all required steps, from mesh separation and crack insertion to local submodeling, stress and displacement mapping, and iterative crack-front update, without manual interaction. The methodology was verified using a mini-compact tension (Mini-CT) specimen as a benchmark case. The numerical results demonstrate the accurate reproduction of stress intensity factors and energy release rates while achieving high computational efficiency through localized refinement. The developed approach provides a robust basis for crack growth simulations of geometrically complex or residual stress-affected structures. Its high degree of automation and flexibility makes it particularly suited for analyzing cracks in clinched and riveted joints, supporting the predictive design and durability assessment of joined lightweight structures.

Abstract Progressive fracture propagation, under coupled cyclic stress-moisture conditions, critically governs stability degradation of rock masses in underground engineering. This study has investigated the mechanical and energy responses of rocks under triaxial cyclic stress. The results demonstrated that with cycle numbers growing, the hysteresis loops exhibited an evolution pattern from dense to sparse. Under lower confining pressure (5 MPa), the hysteresis loops approximated a willow leaf shape, while at higher confining pressure (20 MPa), it transitioned to a shuttle-shaped morphology. The disparity between rocks loading/unloading deformation modulus progressively amplified with its increasing confining pressure. Notably, the axial residual deformation attained a significant magnitude during first cycle but underwent marked attenuation in subsequent cycles. This phenomenon highlighted the critical role of confining pressure in modulating rock’s hysteretic behavior and irreversible deformation. The total energy, for both saturated and dry red sandstone, demonstrated exponential growth in later cycle stages, while the elastic energy maintained a rapid amplification mode throughout entire cycle loading–unloading process. Its dissipative energy also initiated accelerated growth during its later cycles, with its growth curve approximating a steep linear pattern. Moreover, the primary cracks of saturated red sandstone generally exhibited relatively large angles with horizontal direction, and it displayed a smaller proportion of tensile cracks than dry specimens. This contrast highlighted the significant influence of saturation on fracture mechanism and energy partitioning of rocks under cyclic stress, where water–rock interactions fundamentally modified cracks propagation mode and energy redistribution pathway.