Fabrication of water-resistant and high-temperature-tolerant adhesives through synergistic bionic strategy to achieve balanced adhesion and cohesion.

Amplifying endogenous arsenic flux: The role of sediment bulking driven by organic matter mineralization.

An enhanced model for shear strength of UHPC–NSC interfaces considering reinforcement planting

Characterizing the shearing strength of compacted Qiantang River silty clay from a state-dependent perspective

Solid-liquid transition behavior and shear strength degradation mechanisms of deep-sea sediments induced by water content variation and external disturbance

Climate change causes an increase in the temperature of permafrost. This increases the amount of unfrozen water in the permafrost soils, which will reduce their shear strengths. Such reductions may result in the failure of foundations, buildings, pipelines, and other earth structures. Many factors, including temperature, normal stress, plasticity characteristics of soil, and type of soil, impact the shear strength of frozen and unfrozen soils. This study leverages a statistical design of experiments (DoE) to investigate the impact of temperature, normal stress, and soil type on the peak shear strength of frozen soils. The DoE includes input parameters consisting of temperatures ranging from −10°C to +4°C in increments of 2°C, normal stresses of 50, 100, 200, and 300 kPa, and a selection of 10 fine-grained laboratory-prepared soils. The design optimized the 960 experiments required to explore each factor individually to 37 randomized experiments. These experiments were then conducted using a custom temperature-controlled direct shear device. The findings from the DoE were compared with the traditional one-variable-at-a-time (OVAT) approach. It was determined that DoE offers a valuable understanding regarding the importance of individual parameters affecting peak shear strength. Among these parameters, temperature was found the most influential factor, followed by soil type and normal stress. An increase in the temperature decreased the peak shear strength for temperatures between −10°C and −2°C. Further increases in temperature from −2°C to +4°C densify the soil, leading to a slight increase in the peak shear strength. An increase in liquid limit was seen to decrease the peak shear strength. While the DoE approach provides an acceptable analysis of the significance of the various parameters on the peak shear strength, the predicted values were not reliable due to limitations, such as an oversight of critical boundaries and inability to capture the fundamental differences between the behavior of frozen and unfrozen soil.

Effect of concrete compressive strength and column axial load ratio on the shear strength of RC beam-column joints strengthened with embedded bars

Twin nucleation threshold and ideal shear strength in Ni-based superalloys: atomistic insights from layer-dependent and alloying effects

In geotechnical engineering, the mechanical behavior of calcareous soils (CS) is significantly influenced by particle breakage and the resulting change in shape morphology. This study focuses on understanding the characteristics of particle breakage and shear strength of CS by conducting consolidated and drained triaxial compression tests using different initial relative densities and particle size ranges. The morphological parameters of individual particles were quantified before and after each test by using both dynamic image analysis (DIA) and mechanical sieving analysis. The relationship between the deviatoric stress and the axial strain exhibited strain-softening behavior under an effective confining pressure <400 kPa, while the soil demonstrated a gradual transition to strain-hardening behavior with the increase in confining pressure. For CS specimens of initial particle size ranges of 2–5, 1–2, and 0.5–1 mm, the mean peak friction angles were roughly 37°, 39°, and 40°, respectively. The dilatancy angle increased linearly with the initial relative density but decreased linearly with the effective confining pressure. The CS exhibited apparent cohesion due to the particle interlocking effect. The DIA outcomes indicated that the frequency counts of particle sphericity, aspect ratio, and flatness both before and after the experiments closely followed a Gaussian distribution. The frequency counts of convexity after the tests, however, followed an exponential distribution. The overall shape of the CS particle evolved to a subspherical shape with a smoother particle surface after the shear process. The proposed DIA method proved to be accurate in quantifying particle breakage with irregular particle shapes.

Investigation of the shear strength of steel fiber-reinforced concrete beams through a coupled analysis of crack kinematics and shear-resisting mechanisms

Study on shear strength prediction model of glass fiber-improved loess in seasonal frozen regions based on POA-XGBoost

Diagonal-extremum model for shear strength in double steel plate-concrete composite shear wall

Advantages of geopolymers in rock joint grouting reinforcement: experimental study and peak shear strength model

ABSTRACT Laser surface texturing technology is a promising method in modern adhesive engineering due to its non-contact processing and precise controllability. This study utilized nanosecond pulsed laser surface texturing to investigate the impact of laser parameters (power:3–27 W, scanning speed: 100–500 mm/s, scanning spacing: 0.05–0.25 mm) on the mechanical properties and structure-property relationship of AA6061 aluminum alloy/epoxy adhesive joints through multi-scale characterization. The results revealed that varying laser parameters significantly influenced surface morphology, roughness, surface area of the aluminum adherends, and failure modes, consequently affecting joint shear strength. Quantitative analysis of the failure morphology confirmed a distinct transition from interfacial to cohesive failure under optimized laser parameters, which was further corroborated by scanning electron microscopy (SEM) observations of the adhesive anchoring within the micro-grooves and the resultant fracture mechanisms. Optimization using response surface methodology (RSM) identified the optimal process parameters as follows: laser power X1 = 24 W, scanning speed X2 = 200 mm/s, and hatch spacing X3 = 0.08 mm. Under these optimized conditions, the joints exhibited a shear strength of 18.77 MPa, with a mere 3.2% deviation from the RSM predicted value (18.19 MPa), validating the model’s accuracy.

Wide-bandgap (WBG) perovskites offer distinct advantages in constructing efficient perovskite/silicon tandem devices owing to their favorable spectral matching. However, weak adhesion at the perovskite-substrate-buried interface often leads to inferior mechanical stability of WBG devices under prolonged light and thermal stress. Herein, a functional bridging molecule 2,2'-bipyridine-5-carboxylic acid (BCA) is introduced at the buried interface to simultaneously toughen the interface and enable multisite defect passivation. The pyridine and carboxyl groups in BCA synergistically passivate undercoordinated Pb2+ defects of the perovskite layer, while the aromatic bipyridine framework establishes strong π-π interactions with the self-assembled monolayer (SAM). This approach significantly reduces interfacial voids, suppresses nonradiative recombination, and optimizes carrier extraction, thereby boosting the efficiency of WBG perovskite solar cells (PSCs) from 20.30% to 21.83%. Besides, the reinforced interfacial shear strength (from 0.95 to 2.05 MPa) endows the devices with superior thermal stability, retaining 80% of their initial efficiency after continuous thermal aging at 85 °C for 560 h. Our findings provide insights on designing interface toughening layers toward high-efficiency and mechanically stable perovskite devices.

Gel-based materials are promising candidates for flexible sensors in wearable health monitoring owing to their inherent flexibility, conductivity, and biocompatibility. However, integrating rapid fabrication, robust mechanical properties, and strong interfacial adhesion into a single gel system remains a significant challenge. Here, we report a liquid metal nanoparticle-initiated rapid polymerization strategy to fabricate organic-ionogels without external initiators or cross-linkers. The resulting gels exhibit ultrafast gelation (∼3 min), remarkable toughness (∼27 MJ m-3), high lap shear strength (∼2.4 MPa), and reliable strain sensing performance. Density functional theory (DFT) calculations reveal that strong intermolecular interactions, including hydrogen bonding and electrostatic forces, underpin the enhanced mechanical and adhesive properties. Furthermore, we demonstrate the practical utility of these liquid metal-organic-ionogels (LM-AHG) in a wearable health monitoring device (WHMD) integrated with machine learning algorithms. The system enables real-time, high-precision classification of joint rehabilitation stages based on strain signals, achieving 100% accuracy in stage identification. This work provides a rapid and scalable fabrication route for high-performance organic-ionogels and establishes a material-algorithm codesign paradigm for next-generation personalized rehabilitation and smart wearable electronics.

ABSTRACT A new single Co 68 Fe 5 Si 12 B 15 metallic glass silk/epoxy composite (MGSEC) was prepared by vacuum defoaming and curing technology. The interfacial microscopic stress and properties of a Co 68 Fe 5 Si 12 B 15 metallic glass silk (MGS) and epoxy were studied by a combination of tensile experiment and finite element simulation. The surface roughness of the MGS, the equilibrium contact angle (θ equ ), and interfacial shear strength (ISS) of silk and epoxy were tested to study the bonding mechanism of the MGSEC interface. The Raman spectra technique is verified and first innovatively applied to the analysis of the tensile micro‐interface stress. It may develop into a new method for nondestructive testing and damage source location of composite. To further research the stress of the MGS, the finite element simulation of the tensile experiment of the single MGSEC was carried out by using the ABAQUS software. The crack of the MGSEC first appeared at its interface and then the MGS fractured. The numerical simulation results were consistent with the test ones. These study results are of reference significance in predicting both macroscopic and microscopic mechanical properties of the composite and surface coating materials.

The quantitative analysis of key factors influencing the erosion resistance characteristics of colluvial zone soil is a prerequisite for accurately assessing the erosion resistance ability of the soil. Therefore, this study focuses on the reservoir erosion zone of the Guanyinyan Reservoir area in the Jinsha River Basin, which is a large hydropower station. The physicochemical characteristics of the colluvial zone soil (bulk density, moisture content, total porosity, soil texture, pH, organic matter content, and aggregate stability) as well as erosion resistance capabilities (soil erodibility factor K and shear strength) with variations in water level elevation (low, middle, and high elevations) were analyzed. This study quantitatively evaluated the relative importance of soil physicochemical characteristics to soil erosion resistance, identified key influencing factors, and subsequently constructed a comprehensive evaluation model for soil erosion resistance. The research results indicate that: 1) Redundancy analysis (RDA) and correlation analysis reveal that the soil erodibility factor K is significantly negatively correlated (P < 0.01) with total porosity, sand content, organic matter, mean weight diameter (MWD), geometric mean diameter (GMD), water-stable aggregates larger than 0.25 mm (WSA0.25), and dry-sieved aggregates larger than 0.25 mm (DSA0.25). It is also significantly positively correlated (P < 0.01) with percentage of aggregate destruction for aggregates larger than 0.25 mm (PAD), the silt content, and the clay content. However, it was not significantly correlated with the bulk density, moisture content, or pH. The soil shear strength is significantly negatively correlated (P < 0.05) with the moisture content, clay content, and soil erodibility factor K. The shear soil strength is significantly positively correlated (P < 0.05) with the MWD and DSA0.25. 2) Fourteen erosion resistance indicators of the colluvial zone soil in the Guanyinyan Reservoir area were selected, and a comprehensive evaluation model for soil erosion resistance was established on the basis of Principal Component Analysis (PCA). 3) The Comprehensive Soil Erosion Index (CSEI) in the Jinping Gaunyinyan Reservoir erosion zone varies between 0.082 and 0.942 with changes in water level elevation. For different elevations, the comprehensive soil erosion indices are as follows: high (root zone soil) <middle (root zone soil) <high (un-rooted zone soil) <middle (un-rooted zone soil) <low (root zone soil) <low (un-rooted zone soil). At the same water level elevation, with decreasing flooding time, the CSEI of the un-rooted zone soil in the erosion zone increased by 41.03%, 96.91%, and 353.13% compared with that of the root zone soil. In the reservoir erosion zone of the Guanyinyan Reservoir area, the overall Comprehensive Soil Erosion Index (CSEI) decreases with increasing water level elevation. At the same elevation, the CSEI of the un-rooted zone soil is significantly greater than that of the root zone soil, and this difference further increases with decreasing flooding time.

ABSTRACT The objective of this study was to explore the effect of selected gluing parameters such as different wood surface temperature and equilibrium moisture content (EMC), the use of primer, and pressing pressure and duration, on the bondline quality of Norway spruce (Picea abies). Eight various combinations were evaluated for gluing spruce samples using commercial 1-component polyurethane adhesives and compared with control boards that were bonded at standard conditions of 12% EMC, 20°C surface temperature, 0.6 MPa pressing pressure and 75 min pressing duration. Tensile shear strength tests were conducted in accordance with the EN 302-1:2023 standard and revealed a negligible effect of EMC on the bonding strength, while highlighting the pronounced role of pressing pressure. The presence of primer offset the lower surface temperature by providing comparable tensile shear strength to that of the control samples. The microscopic observation of the bondline showed that at lower pressing pressure, adhesive penetration into the wood was limited, leading to low interfacial bonding and formation of voids in the bondline. However, increasing the duration of applied pressure or the application of primer under non-standard bonding conditions resulted in better bondline formation and adhesive penetration, as reflected by the comparable bonding strength to the control samples.

The mechanical performance of Fused Deposition Modeling (FDM)-fabricated polylactic acid (PLA) components is often limited by weak interlayer bonding and low shear strength. This study investigates the effect of ultrasonic-assisted polydopamine (PDA) coating on enhancing the punch shear strength of PLA specimens. Specimens were fabricated with varying printing parameters, including infill density, layer thickness, wall thickness, and printing speed, followed by PDA coating under different ultrasonic vibrational power, coating solution concentrations, and coating duration. Punch shear testing revealed that ultrasonic-assisted PDA-coated (WUAC) specimens exhibited significantly higher punch shear strength than uncoated (WC) specimens, with the most notable percentage improvement (67.2%) observed at 15% infill density due to improved PDA penetration into internal voids. A maximum punch shear strength of approximately 45 MPa was achieved at 800 W ultrasonic vibrational power, 6.0 mg/ml PDA concentration, and 150 min coating time. Surface morphology analysis confirmed that WUAC specimens exhibited a dense and uniform PDA layer, resulting in enhanced interfacial adhesion and improved structural integrity. The findings demonstrate that ultrasonic-assisted PDA coating is an effective post-processing approach for improving the mechanical and adhesion performance of FDM-printed PLA. The results provide a basis for future studies exploring application-specific performance, including biomedical relevance, following appropriate biological evaluation.