Interface debonding performance of precast segmental nano-materials based concrete (PSNBC) beams

2020 ◽  
Vol 10 (8) ◽  
pp. 1317-1327 ◽  
Author(s):  
Xinfeng Yin ◽  
Ming Zhang ◽  
Lei Wang ◽  
Yang Liu
Keyword(s):  
Lead Zirconate Titanate ◽  
High Strength ◽  
Concrete Specimen ◽  
Lead Zirconate ◽  
Epoxy Adhesive ◽  
Interface Debonding ◽  
Nano Materials ◽  
Monitoring Test ◽  
Physical Effects ◽  
Better Than

The precast segmental concrete (PSC) structures and the nano-materials based concrete beams are widely applied to civil engineering. On the other hand, it is well known that nano-materials have physical effects and can significantly improve the concrete properties of cement-based materials. Therefore, the interface debonding performance of precast segmental nano-materials based concrete (PSNBC) beams is investigated in this study. Two concrete specimens with nano-materials and one concrete specimen without nano-materials were prepared and bonded into PSC beams with a high strength epoxy adhesive. The smart aggregates (SAs) made of piezoceramic Lead Zirconate Titanate (PZT) and concrete are used as the intelligent transducer of monitoring test specimen. The PSC beam was loaded periodically by screw jack to simulate the random debonding damage of different degrees. The experimental results show that the interface debonding performance of the concrete specimens with nano-materials is significantly enhanced and better than that of concrete specimens without nano-materials.

scholarly journals Negative Pressure Waves Based High Resolution Leakage Localization Method Using Piezoceramic Transducers and Multiple Temporal Convolutions

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1990 ◽  
Author(s):  
Guangmin Zhang ◽  
Siu Chun Michael Ho ◽  
Linsheng Huo ◽  
Junxiao Zhu
Keyword(s):  
High Resolution ◽  
Lead Zirconate Titanate ◽  
Negative Pressure ◽  
Lead Zirconate ◽  
Signal Duration ◽  
Leakage Detection ◽  
Localization Algorithm ◽  
Large Area ◽  
Leakage Area ◽  
Better Than

The negative pressure wave (NPW) signals generated by a pipeline leakage often have a long signal duration. When these signals are utilized to compute the leakage position, the long signal duration will result in a large area being considered as leakage area. The localization resolution is low. A novel high-resolution localization algorithm is developed for pipeline leakage detection using piezoceramic transducers in this paper. The proposed algorithm utilizes multiple temporal convolutions to decrease the localization functional values at the points close to the leakage, in order to reduce the range of the leakage area revealed by the proposed algorithm. As a result, the localization resolution is improved. A measured experiment was conducted to study the proposed algorithm. In the experiment, the proposed algorithm was used to monitor a 55.8 m pressurized pipeline with two controllable valves and two Lead Zirconate Titanate (PZT) sensors. With the aid of the piezoceramic sensor, the experimental results show that the proposed algorithm results in a resolution which is better than that of the traditional method.

scholarly journals Looseness Monitoring of Bolted Spherical Joint Connection Using Electro-Mechanical Impedance Technique and BP Neural Networks

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1906 ◽  
Author(s):  
Jing Xu ◽  
Jinhui Dong ◽  
Hongnan Li ◽  
Chunwei Zhang ◽  
Siu Chun Ho
Keyword(s):  
Neural Networks ◽  
Lead Zirconate Titanate ◽  
Back Propagation ◽  
Mechanical Impedance ◽  
High Strength ◽  
Lead Zirconate ◽  
Spherical Joint ◽  
High Strength Bolt ◽  
Space Grid ◽  
Joint Connection

The bolted spherical joint (BSJ) has wide applications in various space grid structures. The bar and the bolted sphere are connected by the high-strength bolt inside the joint. High-strength bolt is invisible outside the joint, which causes the difficulty in monitoring the bolt looseness. Moreover, the bolt looseness leads to the reduction of the local stiffness and bearing capacity for the structure. In this regard, this study used the electro-mechanical impedance (EMI) technique and back propagation neural networks (BPNNs) to monitor the bolt looseness inside the BSJ. Therefore, a space grid specimen having bolted spherical joints and tubular bars was considered for experimental evaluation. Different torques levels were applied on the sleeve to represent different looseness degrees of joint connection. As the torque levels increased, the looseness degrees of joint connection increased correspondingly. The lead zirconate titanate (PZT) patch was used and integrated with the tubular bar due to its strong piezoelectric effect. The root-mean-square deviation (RMSD) of the conductance signatures for the PZT patch were used as the looseness-monitoring indexes. Taking RMSD values of sub-frequency bands and the looseness degrees as inputs and outputs respectively, the BPNNs were trained and tested in twenty repeated experiments. The experimental results show that the formation of the bolt looseness can be detected according to the changes of looseness-monitoring indexes, and the degree of bolt looseness by the trained BPNNs. Overall, this research demonstrates that the proposed structural health monitoring (SHM) technique is feasible for monitoring the looseness of bolted spherical connection in space grid structures.

BaRuO3 thin film electrode for ferroelectric lead zirconate titanate capacitors

1999 ◽  
Vol 14 (10) ◽  
pp. 3833-3836 ◽  
Author(s):  
Sang-Mo Koo ◽  
Li-Rong Zheng ◽  
K. V. Rao
Keyword(s):  
Lead Zirconate Titanate ◽  
Pulsed Laser ◽  
Lead Zirconate ◽  
Laser Deposition ◽  
Metallic Electrode ◽  
Axis Orientation ◽  
Pzt Film ◽  
Fatigue Characteristics ◽  
Fatigue Endurance ◽  
Better Than

The characteristics of a ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) capacitor on conductive BaRuO3 thin films deposited by pulsed laser deposition (PLD) were investigated. The BaRuO3 layer grown epitaxially on LaAlO3(100) substrates at a substrate temperature of 700 °C was found to have a resistivity around 145 μΩ cm at 300 K. The subsequently deposited PZT film showed a c-axis orientation perpendicular to the substrate, and the remnant polarization, ΔP (= P* – P^), and coercive field, EC, of the capacitor were 24.7 μC/cm2 and 52 kV/cm, respectively. Fatigue characteristics of the PZT on BaRuO3 electrodes are far better than those obtained with polycrystalline PZT with Pt structures and comparable to those on epitaxial Yba2Cu3O7−x electrodes. With the new metallic electrode, the PZT layer exhibits no serious degradation in fatigue endurance up to 1010 cycles.

scholarly journals Nanostructures formation in ferroelectrics in the process of phase transformation

2014 ◽  
Vol 04 (04) ◽  
pp. 1450031 ◽  
Author(s):  
V. Ishchuk ◽  
N. Spiridonov ◽  
V. Sobolev
Keyword(s):  
Solid Solution ◽  
Phase Transformation ◽  
Lead Zirconate Titanate ◽  
Small Difference ◽  
Lead Zirconate ◽  
Free Energies ◽  
Elastic Stresses ◽  
Interphase Boundaries ◽  
Physical Effects ◽  
20 Nm

Inhomogeneous states caused by the coexistence of the ferroelectric (FE) and antiferroelectric (AFE) phases in lead–zirconate–titanate based solid solutions have been investigated. It has been found that the domains of the FE and AFE phases with sizes of the order of 20 nm to 30 nm coexist in the bulk of the samples due to a small difference in the free energies of these phases. The coherent character of the interphase boundaries (IPBs) leads to the concentration of the elastic stresses along these boundaries. These elastic stresses cause the local decomposition of the solid solution and formation of segregates near the IPBS due to the condition that equivalent positions of the crystal lattice are occupied by the ions with different sizes. The sizes of the segregates formed in this way are of the order 8 nm to 15 nm. Some physical effects caused by the presence of these segregate nanostructures are analyzed and discussed.

Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

1986 ◽  
Vol 44 ◽  
pp. 482-483
Author(s):  
M.L.A. Dass ◽  
T.A. Bielicki ◽  
G. Thomas ◽  
T. Yamamoto ◽  
K. Okazaki
Keyword(s):  
Lead Zirconate Titanate ◽  
Direct Proof ◽  
Lead Zirconate ◽  
Subsolidus Phase ◽  
Pzt Ceramics ◽  
Subsolidus Phase Diagram ◽  
Zirconate Titanate ◽  
Two Phases ◽  
Cbd Method ◽  
Titanate Ceramics

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.

Ion Beam Sputter Deposition Of Ferroelectric Oxide Thin Films

1991 ◽  
Vol 223 ◽  
Author(s):  
Thomas M. Graettinger ◽  
O. Auciello ◽  
M. S. Ameen ◽  
H. N. Al-Shareef ◽  
K. Gifford ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Growth Parameters ◽  
Ion Beam ◽  
Lead Zirconate ◽  
Electro Optic ◽  
Integrated Optical ◽  
Pzt Films ◽  
Ion Beam Sputter Deposition ◽  
Ferroelectric Oxide

ABSTRACTFerroelectric oxide films have been studied for their potential application as integrated optical materials and nonvolatile memories. Electro-optic properties of potassium niobate (KNbO3) thin films have been measured and the results correlated to the microstructures observed. The growth parameters necessary to obtain single phase perovskite lead zirconate titanate (PZT) thin films are discussed. Hysteresis and fatigue measurements of the PZT films were performed to determine their characteristics for potential memory devices.

Mathematical model to predict the characteristics of polarization in dielectric materials: The concept of piezoelectrcity and electrostriction

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Lead Zirconate Titanate ◽  
Dielectric Material ◽  
Strain Curve ◽  
Dielectric Materials ◽  
Lead Zirconate ◽  
Simulation Software ◽  
Constitutive Law ◽  
Basic Material

Model was developed for the prediction of polarization characteristics in a dielectric material exhibiting piezoelectricity and electrostriction based on mathematical equations and MATLAB computer simulation software. The model was developed based on equations of polarization and piezoelectric constitutive law and the functional coefficient of Lead Zirconate Titanate (PZT) crystal material used was 2.3×10-6 m (thickness), the model further allows the input of basic material and calculation of parameters of applied voltage levels, applied stress, pressure, dielectric material properties and so on, to generate the polarization curve, strain curve and the expected deformation change in the material length charts. The mathematical model revealed that an application of 5 volts across the terminals of a 2.3×10-6 m thick dielectric material (PZT) predicted a 1.95×10-9 m change in length of the material, which indicates piezoelectric properties. Both polarization and electric field curve as well as strain and voltage curve were also generated and the result revealed a linear proportionality of the compared parameters, indicating a resultant increase in the electric field yields higher polarization of the dielectric materials atmosphere.

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