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The deformation behavior of uncured thermoset prepreg during hot compaction process was investigated by dividing the whole compaction process into an initial compression stage and the subsequent creep stage. At the compression stage, there existed a strain‐softening phenomenon in the temperature range of 50–90°C, indicating different deformation behavior that is mainly determined by the viscosity of prepreg. Following an appraisal of advantages and limitations of existing compaction models, a combination model consisted of a modified power‐law model including the influence of temperature and the generalized Kelvin‐Voigt model was proposed to describe the deformation behavior of prepreg during compression and creep stage, respectively. Finally, a discussion on the compaction mechanism was conducted to offer some insights into the deformation process. Highlights: Strain‐softening phenomenon occurred during the compaction of uncured prepreg.Proposed combination model captures the deformation of uncured prepreg well.The percolation mechanism dominates prepreg deformation during compaction.The squeeze flow mechanism causes limited thickness reduction of prepreg. [ABSTRACT FROM AUTHOR]

Using self-absorption tests combined with the digital speckle correlation method (DSCM), we investigated the evolution of the deformation field, expansion anisotropy, full-field strain, crack development, and deformation mechanisms in mudstone. During the early moisture-absorbing stage, the displacement field was uneven, accompanied by crack initiation and propagation. By the end of moisture absorption, the horizontal displacement exhibited an approximately 45° zonal pattern along the x-axis, while vertical displacement showed a horizontal zonal distribution. The anisotropy degree of the expansion rate over time mirrored the water absorption curve of mudstone. A three-piecewise linear model was developed to fit the relationship between expansion rate anisotropy and water absorption. Throughout moisture absorption, the average linear strain variation followed the water absorption trend, with the final mean linear strain significantly decreasing as sample height increased. The maximum εxx occurred at the crack tip, and the strain localization band distribution indicated crack development. The maximum εyy aligned with mid-span theory, showing zero vertical displacement. Deformation of mudstone during moisture absorption involved both pore water adsorption and the expansion of clay minerals within the matrix. This study introduces a novel method for examining the hygroscopic expansion and cracking behavior of red-bed mudstone, providing crucial insights into disaster mechanisms and engineering stability in red-bed regions. [ABSTRACT FROM AUTHOR]

Seepage-initiation-braking-type (SIBT) landslides are the majority of reservoir landslides in the Three Gorges Reservoir Area in China that involve gradual deformation in response to water level (WL) and rainfall rather than experiencing an abrupt failure and sliding directly into the river, highlighting the complex nature of this landslide. Here, a physical model test with the rainfall and the fluctuation of WL was conducted on a representative SIBT landslide, Huangtupo Linjiang No. 1 landslide (HTPLJ1). The changes in pore water pressure, earth pressure, and overall displacement of the landslide model were monitored by a monitoring system. The results revealed distinct stages in the landslide model: impoundment-induced deformation, preliminary sliding, stagnation and stability, re-initiation, short stability, and accelerated sliding to failure. Combined with monitoring system analysis, the rainfall infiltrations destabilized the shallow landslide by reducing the effective stress, while impoundment increased pore water pressure, leading to buoyancy-driven effects. However, the most notable deformations occurred during the WL drawdown stages, when seepage drag force induced by the low permeability of the sliding mass triggered more pronounced deformations. The deformation mechanism of HTPLJ1 with SIBT is attributed to a bulged slope toe induced by the seepage drag force, leading to increased effective stress along the resisting section and temporary stabilization. The site geological investigations and monitoring data indicated continuous buoyancy-driven effects and a higher sensitivity to seepage-driven effects in HTPLJ1. It can be inferred that the SIBT landslides undergo repetitive deformation characterized by "dragging and compression," which leads to initiation and stagnation. [ABSTRACT FROM AUTHOR]

Grain boundary (GB) plastic deformation is a critical deformation mode that can significantly affect the microstructure and mechanical properties of metals. Given its importance, numerous studies have been conducted over the past few decades to investigate the atomistic mechanism of GB plasticity, which includes GB migration, GB sliding, and grain rotation. These three deformation modes typically occur simultaneously and interact cooperatively. Despite substantial advancements in understanding the atomic‐scale mechanisms of GB plasticity, there is a scarcity of review papers addressing the in situ atomic‐scale mechanisms of GB plasticity. This work aims to provide a comprehensive overview of the atomistic mechanisms of GB plasticity in metals, detailing modes predicted by theoretical models and molecular dynamics (MD) simulations, as well as discussing mechanisms verified by in situ atomic‐scale experiments. Additionally, it examines the factors influencing GB deformation. The authors intend for this review to serve not only as a valuable resource for researchers in the field of nanocrystalline (NC) metals but also as a textbook for educating graduate students. [ABSTRACT FROM AUTHOR]

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Many reservoir landslides have started undergoing rapid deformation in the Baihetan Reservoir region (BRR) by the complex structural background and initial impoundment, posing a significant risk to human life and infrastructure. In order to understand the intrinsic relationships between the geological structure, reservoir water, and landslide deformation, a detailed analysis of the Gengdi landslide along fault zones during the first water level circulation fluctuation in the BBR was conducted. The investigation was conducted systematically by means of comprehensive in situ monitoring, drilled cores, adit, high-density resistivity method, field investigations and engineering mapping, and aerial photographs. The Gengdi landslide showed a characteristic type of bending flowing and fracturing. The shear outlets of the landslide are the top and bottom of the fault gouge respectively. Hydrodynamic pressure and fault gouge softening are the trigger factors of the landslide. The main deformation of the landslide was along a deep fault zone. The maximum rate of landslide deformation occurred during the period when the reservoir water level fluctuation between the top and bottom of fault gouge. The findings revealed that the reservoir water level fluctuation caused the compression of the fault gouge and dragged the upper rock mass of fault zone. This study provided a detailed geological model for the formation of the landslide in fault zone. The likelihood of large-scale landslides is significantly high with the current deformation rate of the Gengdi landslide. Therefore, the analysis of reactivation mechanism and control of this type of landslide should be strengthened. [ABSTRACT FROM AUTHOR]