Study on Interaction of RC Pile-Soil with High Reinforcement Ratio of Integral Abutment Bridges under Quasi-Static Test

In order to improve the ability of the reinforcement concrete (RC) pile foundation of integral abutment to absorb the horizontal reciprocating deformation under the action of temperature or earthquake, a pseudo-static low cycle test on interaction of pile-soil with high reinforcement ratio was carried out. The failure location, hysteresis curve, skeleton curve and horizontal deformation of three piles with different reinforcement ratios were compared. The test results show that, with the increase of the reinforcement ratio, the crack of the RC pile develops along the pile body to the depth, and the pile body failure area and the position where the maximum bending moment moves down, the crack resistance of the pile body is improved, and the effective interaction pile length increases; The test results also show that the hysteresis curve of the model pile becomes fuller with the increase of the reinforcement ratio, compared with the RCP-1 specimen with the lowest reinforcement ratio, the equivalent viscous damping ratio of the RCP-3 specimen is increased by 31.6%, and the energy dissipation capacity is improved. In addition, with the increase of the reinforcement ratio, the bearing capacity and deformation capacity of model piles are greatly improved. Compared with RCP-1 specimen, the ultimate bearing capacity of RCP-3 specimen increased by 150%, and the corresponding ultimate displacement increased by 153%. Increasing reinforcement ratio can significantly improve the mechanical properties and deformation capacity of RC pile.

An Experimental Study on the Seismic Performance of High-Strength Composite Shear Walls

In order to study the seismic performance of high-strength concrete composite shear walls with embedded steel strips, four tests for high-strength concrete composite shear walls with embedded steel strips (SPRCW-1 to SPRCW-4) were constructed and tested. Based on the test results, a discussion is provided in the present study on the hysteresis curve, backbone curves, and strain of steel plate and distributed reinforcement of high-strength concrete mid-rise and high-rise composite shear walls with embedded steel strips under different steel ratios and different steel strip positions. The test results reveal that in high-strength composite shear walls with embedded steel strips, the ductility of the test specimen can be effectively improved when the ratio of the steel strip reaches a certain level. In parallel, when the embedded steel strip is placed on both sides of the walls, the steel strip can function better. The ultimate displacement is better than when the steel strip is placed in the middle of the walls, and can effectively improve the seismic performance of the walls. The scheme with embedded steel strips is more convenient and economical for construction, which is suitable for popularization and application in middle-high buildings in highly seismic regions.

An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

An innovative passive energy damper is introduced and studied experimentally and numerically. This damper is designed as the main plate for energy absorption which is surrounded by an octagon cover. In addition to simplicity in construction, it can be easily replaced after a severe earthquake. Experimental test results, as well as finite element results, indicated that, by connecting the cross-flexural plate to the main plate, the mechanism of the plate was changed from flexural to shear. However, the cross_flexural plate always acts as a flexural mechanism. Changing the shear mechanism to a flexural mechanism, on the other hand, increased the stiffness and strength, while it reduced the ultimate displacement. Comparing the hysteresis curve of specimens revealed that models without cross_flexural plates had less strength and energy_dissipating capability than other models. Adding the flexural plate to the damper without connecting to the main plate improved the behavior of the damper, mainly by improving the ultimate displacement. Connecting the cross plate to the web plate enhanced the ultimate strength and stiffness by 84% and 3.9, respectively, but it reduced the ductility by 2.25. Furthermore, relationships were proposed to predict the behavior of the dampers with high accuracy.

Effect of sintering temperature on structural, magnetic, dielectric and optical properties of Ni–Mn–Zn ferrites

Spinel ferrite Ni[Formula: see text]Mn[Formula: see text]Zn[Formula: see text]Fe2O4 was prepared by a conventional ceramic process followed by sintering at three different temperatures (1050[Formula: see text]C, 1100[Formula: see text]C and 1150[Formula: see text]C). X-ray diffraction (XRD) investigations stated the single-phase cubic spinel structure and the FTIR spectra revealed two prominent bands within the wavenumber region from 600 cm[Formula: see text] to 400 cm[Formula: see text]. Surface morphology showed highly crystalline grain development with sizes ranging from 0.27 [Formula: see text]m to 0.88 [Formula: see text]m. The magnetic hysteresis curve at ambient temperature revealed a significant effect of sintering temperature on both coercivity ([Formula: see text] and saturation magnetization ([Formula: see text]. Temperature caused a decrease in DC electrical resistivity, while the electron transport increased, suggesting the semiconducting nature of all samples and that they well followed the Arrhenius law from which their activation energies were determined. The values of Curie temperature ([Formula: see text] and activation energy were influenced by the sintering temperature. Frequency-dependent dielectric behavior (100 Hz–1 MHz) was also analyzed, which may be interpreted by the Maxwell–Wagner-type polarization. The UV–vis–NIR reflectance curve was analyzed to calculate the bandgap of ferrites, which showed a decreasing trend with increasing sintering temperature.

The Effect of Arrive Angle of External Magnetic Field on The Shape of Hysteresis Curve Permalloy Ni80Fe20 By Simulation

Magnetic sensor is a type of sensor that utilizes changes in resistance caused by changes in the magnetic field H or B. One of the suitable magnetic materials to be used as a study material for making magnetic sensors is permalloy Ni80Fe20. The reading error of the magnetic sensor of the Ni80Fe20 permalloy material affects hysteresis curve of the material and requires correction of the angle of incidence of the external magnetic field in order to provide accurate results on the storage media. In this our current research using Finite Difference OOMMF, we investigated the effect of the angle of incidence of the external magnetic field (H) on the hysteresis curve was carried out on an application based on. The research was conducted by reviewing the parameter literature of the Ni80Fe20 permalloy material and then compiling it in a script and simulating it on an application based on Finite Difference OOMMF. The data obtained from the simulation are normalized magnetization (m), external magnetic field H and coercivity field (Hc) which have been influenced by the angle of incidence. The results of the hysteresis curve at a size of 5 nm with a variation of the angle of incidence 0o are indicated by the value of the external magnetic field H of 10000 mT to -10000 mT with a coercive field Hc of 5000 mT to -5000 mT. The normalized magnetization value m is 1 to -1. The variation of the angle of incidence of 30o produces a coercive field Hc of -108.3 mT to 108.3 mT and a normalized magnetization of 0.86 to -0.86. The 45o incident angle variation produces a coercive field Hc -88.4 mT to 88.4 mT and a normalized magnetization of -0.7 to 0.7

Experimental and Finite Element Analysis of External ALC Panel Steel Frames with New Semi-Rigid Connector

In this paper, a new ALC panel connector was proposed. It has a good engineering economy and high fault tolerance. A quasistatic loading experiment was carried out to verify the feasibility of the external ALC panel steel frame under seismic loading. The test phenomena, hysteretic curve, skeleton curve, stiffness degradation, and energy dissipation of two sets of full-scale specimens were analyzed and discussed. Moreover, the simulation of pendulous Z-panel connectors with different thicknesses was carried out using ABAQUS software. The comparison reveals that the semi-rigid connection has a full hysteresis curve, good energy dissipation capacity, and a 15% increase in peak load capacity. Finally, similar results for different thicknesses in the use of pendulous Z-panel connectors reveal that using the 6 mm connector may be the most economical solution for engineering.

Albumen-assisted Synthesis of Nanocrystalline Nickel Ferrite Photocatalyst

As a simple step to remove the polluting dyes in aqua ecosystem, NiFe2O4 nanoparticles well known for their ferromagnetic properties, low conductivity and high electrochemical stability were prepared by simple auto combustion method using egg white as fuel via green synthesis route. The structural, morphological and magnetic properties of prepared NiFe2O4 was analyzed. The desirable phase purity of the prepared spinel ferrite was deliberated by X-ray Diffractometer (XRD), Fourier Transform Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive and Vibrating Sample Magnetometer (VSM). XRD predicts the phase formation, particle size and lattice parameter of the spinel ferrite. The FTIR spectrum confirms the ferrite structure. The morphological and elemental analysis was made using SEM and EDAX. The hysteresis curve reveals the magnetic properties, such as remanence magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms). The photocatalytic efficiency of the synthesized samples was determined from degradation of methylene blue dye. The whole process was monitored using spectrophotometer at regular intervals of time. The maximum photocatalytic degradation efficiency for NiFe2O4 is around 95.6 %. Keywords: NiFe2O4, Ferrite, Green synthesis, Egg white, Combustion, Photocatalyst.

Numerical Study on the Mechanical Properties of Transmission Tower K-Joints under Cyclic Loading

During the vibration of a transmission tower, the joints will be subjected to a reciprocating load. To obtain the accurate state of the transmission tower under the load, the mechanical properties of the joints under the vibration load must be considered. In this paper, the mechanical properties of typical K-joints in transmission tower structures are studied by numerical simulation. The failure mode of the K-joint under cyclic loading is also analyzed. The mechanical properties of the K-joint are discussed from the aspects of hysteretic characteristics, stiffness degradation, energy dissipation capacity, and ductility evaluation, and the influencing factors are discussed. The results show that the failure mode of the K-joint is related to the bolt grade and steel strength. When analyzing K-joints, the moment-rotation hysteresis curve should be combined with the realistic parameters of joints to consider the hysteretic behavior of the K-joint. The results provide a theoretical reference for the accurate modeling of transmission towers.

Effective Method to Measure and Inspect the Hysteresis Loss of a Transformer

<p class="Abstract"><span lang="EN-US">This paper presents a study on the significance of source side harmonics and their effects on transformers. Source side harmonics are typically present in power electronic sources which are commonly used in renewable applications. The continued outcome of source side harmonics is observed on the hysteresis curve of a transformer. Single-phase transformers are used in the proposed study to determine the effect of harmonics on magnetization and demagnetization cycles using an electronic operational amplifier-based integrator circuit. A technique is also presented for effectively storing and plotting the hysteresis curve from the measured data. After the hysteresis curve is obtained, it is compared with standard data and a conclusion is obtained from the results about the presence of harmonics in the source. The hysteresis curve is thus found without removing the transformer from operation. The study also proposes a modified hysteresis model for the transformer considering the effect of source harmonics. The proposed study is an effective tool for easy measurement and detection of harmonics. The <em>MATLAB/Simulink</em> based simulations with suitable experiments validate the proposed study.<em></em></span></p>

Permeability Characteristics of Water-Sand Seepage in Fracture by Experiment

Studies on the seepage characteristics of water-sand cracks are of great significance to reveal the mechanisms of water and sand inrush. Using a self-made water-sand fracture seepage test instrument, a water-sand seepage test was carried out, and the permeability of water and sand in the fracture was determined. The hysteresis characteristics of water-sand flow in the fracture were obtained after the required permeability was attained. The results show that the hysteresis curve changes from type I to type IV with the increase in sand particle size and concentration. The hysteresis parameters are described by the maximum hysteresis Gp ∗ and the hysteresis area S, both of which show an increasing trend with the increase in sand particle size and concentration; however, this increase is not synchronous. The average velocity and turbulent kinetic energy distribution of the water-sand fluid on the fracture cross section are greatly affected by the particle size and concentration of the volume of sand. This study can provide a reference for further study of water inrush from a shallow coal seam. Through simulation, it is found that the particle size has a great influence on the seepage velocity, and the influence near the side wall surface is greater than that in the middle position.