scholarly journals Electromechanical Response and Residual Thermal Stress of Metal-Core Piezoelectric Fiber /Al Matrix Composites

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5799
Author(s):  
Yinli Wang ◽  
Tetsuro Yanaseko ◽  
Hiroki Kurita ◽  
Hiroshi Sato ◽  
Hiroshi Asanuma ◽  
...  
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Composite Materials ◽  
Output Voltage ◽  
Residual Thermal Stress ◽  
Piezoelectric Composite ◽  
Concentrated Load ◽  
Position Detection ◽  
Al Matrix ◽  
Piezoelectric Fiber

It is well known that the curing residual stress induced during a fabrication process has a great influence on the performance of piezoelectric composite devices. The purpose of this work was to evaluate the residual thermal stress of lead zirconate titanate piezoelectric fiber aluminum (Al) matrix (piezoelectric fiber/Al) composites generated during fabrication numerically and experimentally and to understand the effect of the residual thermal stress on the electromechanical response. The three-dimensional finite element method was employed, and the residual stress generated during the solidification process of the Al matrix was calculated. The output voltage was also calculated in the analysis when putting stresses on the composite materials in the length direction of the piezoelectric fiber. It was shown that the cooling from higher temperatures increases the electromechanical conversion capability. Furthermore, we also performed the simulation, and we recorded the output voltage under concentrated load to investigate its application as a load position detection sensor, and we also discussed the influence of the position by changing the modeling with a different fiber position in the Al. The residual stress of hot press molded piezoelectric fiber/Al composite was then measured, and the comparison was made with the calculated values. The simulation results revealed that our model predictions reproduced and explained the experimental observations of curing residual stress. After this study, similar models of composite materials can be analyzed by this simulation, and the result can be used to design piezoelectric composite materials.

scholarly journals Simulation of the Residual Stress of the Y2O3/Al2O3 Composite Deuterium Permeation Barrier under Thermal Shock

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kezhi Huang ◽  
Weijing Wang ◽  
Qinghe Yu ◽  
Lei Hao ◽  
Jing Mi ◽  
...  
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Thermal Shock ◽  
Principal Stress ◽  
Stress Singularity ◽  
Residual Thermal Stress ◽  
Al2o3 Coating ◽  
Element Analysis ◽  
Al2o3 Layer ◽  
Y2o3 Coating

A deuterium permeation barrier is an essential part in the core component of nuclear reactors. It can protect the structure made of steel from being penetrated by deuterium in a fusion reactor. However, residual stress induced in the operation would dramatically influence the mechanical endurance of the coating, threatening the safety of the facilities. In this paper, finite element analysis was conducted to investigate the residual stress in nanoscale Al2O3 and Y2O3 coatings and their composites under thermal shock, from 700°C to 25°C. The max principal stress is assumed as the cause of crack initiation in the coating, because ceramics are brittle and fragile under tensile stress. Max shear stress and max Mises stress in the systems are also analyzed, and the effect of thickness in the range 100 nm to 1000 nm was investigated. The max principal stress in Al2O3 coating reaches its maximum value, 1.33 GPa, when the thickness of coating reaches 450 nm. And the max principal stress decreases at a very low rate as the thickness increases exceeding 450 nm. The max principal stress in Y2O3 coating increases rapidly as the thickness increases when the thickness of the coating is below 250 nm, and the max principal stress is at about 0.9 GPa when the thickness exceeds 500 nm. The max principal stress in the Y2O3/Al2O3 (150 nm) composite coating occurs in the Al2O3 layer and shows no difference from the single layer of 150 nm thick Al2O3 coating. The max principal stress site of all three kinds of coating is located at the edge of the coating 25 nm away from the interface. The result shows that residual thermal stress in the coating increases as the thickness increases when the thickness of the coating is below 200 nm due to the stress singularity of the interface. And as the thickness exceeds 500 nm, the increase in thickness has little impact on the residual thermal stress in the coating. Coating an Y2O3 top layer will not introduce any more residual thermal stress under the thermal shock condition. The Y2O3 coating causes much less residual stress under thermal shock compared with Al2O3 owing to its much lower Young’s modulus. The max principal stress in the 300 nm thick Y2O3 coating is 0.85 GPa while that of the Al2O3 coating is 1.16 GPa. The max residual stress of the composite Y2O3/Al2O3 (150 nm) coating is determined by the Al2O3 layer.

Investigation of Fabrication Condition of Metal Matrix Piezoelectric Composite Using Surface Oxidized Metal Fiber As Internal Electrode

2020 ◽  
Author(s):  
Tetsuro Yanaseko ◽  
Isao Kuboki ◽  
Hiroshi Sato ◽  
Hiroshi Asanuma
Keyword(s):  
Metal Matrix ◽  
Output Voltage ◽  
Mechanical Energy ◽  
Piezoelectric Ceramics ◽  
Piezoelectric Composite ◽  
Conversion Function ◽  
Electrode Structure ◽  
Metal Core ◽  
The Matrix ◽  
Piezoelectric Fiber

Abstract Piezoelectric ceramics are widely used as sensors and actuators because of their excellent electrical-mechanical energy conversion function. However, the piezoelectric ceramics have the disadvantage of being brittle and not suitable for applications where a large load is applied. To overcome this problem, a metal matrix piezoelectric composite in which piezoelectric ceramics are embedded in a metal matrix with excellent strength has been developed. The developed metal matrix piezoelectric composite is fabricated from a metal-core piezoelectric fiber as the piezoelectric material and aluminum matrix, the metal-core and metal matrix are used as the electrodes. The metal-core piezoelectric fiber/aluminum composite has an output voltage anisotropy with respect to strain, thus, it has unique characteristics as a sensor. Previous studies revealed that this output voltage anisotropy depends on the electrode structure, suggesting that the output voltage characteristics can be adjusted by designing the electrode structure. However, the metal-core piezoelectric fiber is manufactured by extrusion method, and the cross-sectional shape cannot be changed, that is, the output voltage characteristic design is impossible. Therefore, a metal matrix piezoelectric composite that can be designed output voltage characteristics by using surface oxidized metal fibers as internal electrodes has been developed. In this study, the fabrication conditions of this metal matrix piezoelectric composite were investigated. The embedding temperature and pressure were changed, and the structure of the resulting composite was observed and elemental analysis was performed to confirm the presence of chemical reaction between the matrix and the piezoelectric ceramics. As a result, it is found that a range of conditions where the oxide films and the piezoelectric ceramics can be embedded in the matrix without damage.

Analysis of Thermal Residual Stress on Large Thickness Polypropylene Joints as in a Reel-Lay System

2016 ◽  
Author(s):  
Kristopher Reaves ◽  
Raresh Pascali ◽  
David Rypien
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Initial Study ◽  
Residual Thermal Stress ◽  
Thermal Shrinkage ◽  
Current Stress ◽  
Large Thickness ◽  
Insulation Thickness ◽  
The Common ◽  
Resultant Stress

The purpose of this document is to be an initial study into the affects that increased insulation thickness requirements have on a typical field joint. An observed increase in joint failures has begun to occur with larger insulation thickness requirements which requires justification as to a possible and probable cause. The method of failure that is looked into in this document is the increase in comparative stress at the bonding joints caused by the increased stress of the comparatively increased thermal shrinkage and resultant residual thermal stress. This is analyzed through an ABAQUS simulation for current stress of the common 3in insulation thickness and the resultant stress of increasing the insulation to a 4 in thickness. The increase in stress upwards of 30% can be a cause of concern when paired with bending due to the requirements of reel lay installation methods.

Residual Stress Analysis in Curing Process of COG Module

2010 ◽  
Vol 118-120 ◽  
pp. 434-438
Author(s):  
Liu Bing Wang ◽  
Hong Gao ◽  
Jian Ma ◽  
Xu Chen
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Deformation Process ◽  
Equivalent Stress ◽  
Heat Transfer Process ◽  
Curing Temperature ◽  
Residual Thermal Stress ◽  
Curing Process ◽  
Particle Deformation ◽  
Heat Transformation

In this study, the bonding reliability of the COG devices was studied. A finite element analyses model was established to study the curing process of COG module. The equivalent stress of the different locations of the package structure and the change of the temperature distribution with time were studied. The heat transfer process and the conductive particle deformation process were displayed through the simulation. The results show that the curing process is the heat transformation and particle deformation process. The residual stress generated by the temperature difference between the curing temperature and the operated temperature. The results show that the maximum residual stress is in the most distorted places of the conductive particles. The maximum residual thermal stress was studied with different bump pitch (35μm 30μm 25μm and 20μm) and the size of the particles (5μm, 4μm and 3.5μm). It shows that for a certain size of the particles, the maximum residual thermal stress will decrease when the bump pitch decreases. For a certain bump pitch, the maximum residual thermal stress will decrease when the size of the particles decrease.

Effects of residual thermal stress on mechanical behavior of cermets with different grain sizes

2021 ◽  
pp. 117428
Author(s):  
Jinghong Chen ◽  
Chong Zhao ◽  
Hao Lu ◽  
Yanan Li ◽  
Xuemei Liu ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Mechanical Behavior ◽  
Residual Thermal Stress ◽  
Grain Sizes
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