We performed uniaxial compression tests on coal–rock, rock–coal, and rock–coal–rock bi-material samples. studied their mechanical behavior using an acoustic emission monitoring digital speckle strain measurement systems. The average compressive strengths of the rock–coal–rock, rock–coal samples were 20.54 MPa, 14.28 14.03 respectively. strength coal determines overall sample. However, greater than that by 11.76%, 10.19%, 31.84%, A crack in part a sample can develop spread to rock part, thus...

We report the comparative in situ fracture toughness testing on single-edge V/U-notched multilayer graphenes and boronitrenes a high-resolution transmission electron microscope (HRTEM). The nanostructures of notch tips edges tested specimens are unambiguously resolved using HRTEM. By analyzing tip stresses finite element method, is determined to be 12.0 ± 3.9 5.5 0.7 MPa√m, respectively, taking into account blunting effects.

The fundamental shear horizontal (SH0) wave in plate-like structures is of great importance non-destructive testing (NDT) and structural health monitoring (SHM) as it non-dispersive, while excitation or reception SH0 waves using piezoelectrics always a challenge. In this work, we firstly demonstrate via finite element simulations that face-shear superior to thickness-shear driving SH waves. Next, by newly defined d24 PZT wafer an actuator d36 PMN-PT wafers sensors, pure was successfully...

A one-dimensional pencil-like magnetoelectric (ME) sensor prototype is proposed which consists of a magnetostrictive cylinder, truncated conical spacer, and piezoelectric disk assembled in rigid frame. By adopting the displacement-transfer mode this sensor, not only strain loss at ME interface avoided but also volume fractions both phases can be adjusted broader range. Using nonlinear model linear model, coupling performance systematically analyzed using lead titanate zirconate (PZT) disks...

The fundamental shear horizontal (SH0) wave in plate-like structures is extremely useful for non-destructive testing (NDT) and structural health monitoring (SHM) as it non-dispersive. However, currently, the SH0 usually excited by electromagnetic acoustic transducers (EMAT) whose energy conversion efficiency fairly low. face-shear (d36) mode piezoelectrics more promising excitation, but this cannot appear conventional piezoelectric ceramics. Recently, modifying symmetry of poled PbZr1−xTixO3...

One-dimensional single-crystal nanostructural nickel selenides were successfully in situ grown on metal foils by two simple one-step solvothermal methods, which formed NiSe/Ni counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The foil acted as the source reaction process, a supporting substrate, and an electron transport "speedway". Electrochemical testing indicated that top 1D NiSe exhibited prominent electrocatalytic activity I3– reduction. Due to metallic conductivity of Ni...

Excitation of single fundamental torsional wave T(0, 1) mode is practical importance in inspecting or monitoring the structural integrity pipelines, as only non-dispersive pipe-like structures. This work presents a piezoelectric ring array to excite and receive which made up series equally-spaced face-shear d24 PZT elements around pipe. Firstly, we proposed that can be excited by ring, when number slightly greater than n, where F(n, 2) highest circumferential order flexural within frequency...

This paper proposes a novel method for motion multi-object matching and position estimation in the absence of salient features based on unsynchronized image sequences. Our proposed aims to address issues traditional feature that requires static objects, need synchronized images when epipolar constraint is used. Firstly, sequences are captured using three calibrated cameras, each object, spatial planes established multi-images. Each pair determines candidate trajectory very object calculates...

Piezoelectric actuators are increasingly used in fuel injectors due to their quick response, high efficiency, accuracy, and excellent repeatability. Current understanding of thermo-electro-mechanical performance under dynamic driving conditions appropriate for injection is, however, limited. In this paper, the soft Lead Zirconate Titanate (PZT) stack is experimentally investigated over a temperature range -30°C 80°C, electric fields up 2.0 kV/mm (using an AC drive method biased DC offset),...

The piezoelectric face-shear (d36) mode may be the most useful shear in piezoelectrics, while currently this can only exist single crystals of specific point groups and cut directions. Theoretically d36 coefficient vanishes ceramics because its transversally isotropic symmetry . In work, we modified poled PZT from to orthogonal through ferroelastic domain switching by applying a high lateral stress along "2" direction holding for several hours. After removing compression, d31 is found much...

The fundamental shear horizontal (SH0) wave in plates is of great importance the field nondestructive testing (NDT) and structural health monitoring (SHM) since it unique non-dispersive guided mode. For practical applications, a phased array system based on omnidirectional SH0 transducers most useful as can cover wide range plate. However, so far very few SH have been developed. In this work, we proposed an piezoelectric transducer (OSH-PT) thickness poled ring. ring equally divided into...

Abstract The microenergy harvesting based on magneto‐mechano‐electric (MME) coupling is an emerging technology for powering wireless Internet of Things (IoT) devices because it capable simultaneously magnetic field energy and mechanical energy. However, further improvement in output power conventional cantilever‐structured MME harvesters has met with considerable difficulties due to the inherent, high loss single‐mode operation. To solve predicament, here, this work presents a symmetric,...

Abstract Cleats are the main channels for fluid transport in coal reservoirs. However, microscale flow characteristics of both gas and water phases primary cleats have not been fully studied as yet. Accordingly, local morphological features cleat were determined using image processing technology a transparent structure model was constructed by microfluidic lithography multiphase visualization test system. Besides, effect microchannel tortuosity on two‐phase analyzed this study. The results...

Saturated domain orientation textures of three types pseudocubic (tetragonal, rhombohedral, and orthorhombic) ferroelectric ceramics after complete electric uniaxial tension (compression) poling is studied analytically in this paper. A one-dimensional distribution function (ODF) the polar vectors explicitly derived from uniform inverse pole figures field axes on a stereographic projection with respect to fixed crystallite coordinates. The analytical ODF used obtain solutions saturated...

Mechanical depolarization of poled lead titanate zirconate (PZT) ceramics was conducted at a series temperatures from 25 to 180 °C in temperature-controlled silicon oil tank. Both the longitudinal strain and polarization bar-shaped PZT samples were measured during uni-axial compression up 400 MPa. It is found that both stress-induced switchable decrease steadily with increasing temperature. Unpoled also tested strains follow rule similar ones but smaller magnitude. By measuring P–E...