scholarly journals Ultrasonic Sensors Enabling Early Detection of Emergency Trends and Analysis of Structure Inclination and Stability by Means of Highly Accurate Level Measurements

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1789
Author(s):  
Leszek Ornoch ◽  
Paweł Popielski ◽  
Andrzej Olszewski ◽  
Adam Kasprzak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Early Detection ◽  
Water Levels ◽  
The Finite Element Method ◽  
Ultrasonic Sensors ◽  
Temperature Changes ◽  
New Models ◽  
Object Behavior

Building inclinations can be measured through the use of ultrasonic hydrostatic levelers. These are used to measure long-term relative displacements of vertical parts of structures and utilize the principle of communicating vessels (similar to the classic water scales). The presented ultrasonic displacement measurement technique was developed by Ultrasystem in the 1990s and was applied to several objects in Poland. Long-term measurements enabled the development of a model of object behavior under the influence of various factors. Among these are the annual cycle of temperature changes, fluctuating water levels, turbine chamber emptying, etc. Such a model can facilitate the prediction of failure based on the appearance of changes deviating from typical behavior (e.g., a much stronger dependence of the inclination as a function of the water level). The results obtained with the help of ultrasonic sensors enable the observation of subtle deformations of the object, which is valuable when developing and calibrating new models of the object (e.g., by means of the finite element method).

scholarly journals Models of stents – Comparison and applications

2007 ◽  
pp. S115-S121
Author(s):  
J Záhora ◽  
A Bezrouk ◽  
J Hanuš
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Model ◽  
Model Evaluation ◽  
Structural Mechanics ◽  
Theoretical Background ◽  
Measurement Equipment ◽  
The Finite Element Method ◽  
Basic Properties ◽  
New Models

The aim of this study was to analyze the possibilities of various types of stent modeling and to develop some new models. A brief survey of basic properties of stents and a list of basic designs of stents is presented. Two approaches to stent modeling were identified. Structural mechanics is the theoretical background of our analytical model of a spiral stent. The finite element method was also used. The measurement equipment for model evaluation was developed.

Development of a Compact Deformable Mirror Using Push-Pull Actuators

2014 ◽  
Vol 613 ◽  
pp. 200-203
Author(s):  
Hiroki Shimizu ◽  
Keitaro Tanaka ◽  
Yuuma Tamaru
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Piezoelectric Actuators ◽  
Practical Method ◽  
Simulation Method ◽  
Deformable Mirror ◽  
The Finite Element Method ◽  
Convex Shape ◽  
Long Term Stability

A small deformable mirror which realizes concave shape as well as convex shape has been developed. In addition, this deformable mirror was developed to realize long term stability. For this purpose, a new push-pull actuator using two multilayered piezoelectric actuators aligned inline was designed. In this process, a practical method for simulating the property of piezoelectric actuator in the finite element method was proposed. From the experimental results, it was confirmed that newly developed deformable mirror has the ability to make complex profiles. Furthermore, efficiency of proposed simulation method was also confirmed.

scholarly journals Assessment of the reinforcing ability of a composite bandage for modern pipeline repair systems

2021 ◽  
Author(s):  
Eugen Savchuk ◽  
Viktor Rubashevskyi ◽  
Sergiy Shukayev
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Comparative Analysis ◽  
Service Life ◽  
Close Agreement ◽  
The Finite Element Method ◽  
Strain Ageing ◽  
Term Operation ◽  
Reinforced Steel

Abstract. The long-term operation of pipelines, which, in many cases, exceeds their regulatory service life, causes the strain ageing of metal, as well as the appearance of local mechano-corrosive damages. In this regard, the use of composites to reinforce worn pipelines constitutes one of today’s most promising technologies. In this study, a comparative analysis was performed between the composite-reinforced steel pipe calculations that were conducted using the finite element method (FEM), and those that were conducted in accordance with the DSTU ISO 24817:2019 standard. The FEM numerical calculations were carried out using the complete factorial experiment design (consisting of three factors at three levels, with twenty-seven calculations in total). Based on the results of these calculations, a regression model was developed to assess the circular deformation of the pipe’s outer surface depending on the thickness of the bandage, the thickness of the pipe, and the internal pressure. The FEM calculations were found to be in close agreement with analytical results.

scholarly journals Stereometry of compressed conoids and physical adequacy of q8 element bases

2021 ◽  
Vol 3 (134) ◽  
pp. 40-48
Author(s):  
Anatoliy Khomchenko ◽  
Olena Lytvynenko ◽  
Oleh Dudchenko ◽  
Igor Astionenko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Trigonometric Functions ◽  
The Finite Element Method ◽  
Standard Element ◽  
Elegant Method ◽  
New Models ◽  
Historical Importance ◽  
Serendipity Elements

The paper considers new models of bases of serendipity finite elements (FE) Q8. The standard element Q8 has been used in the finite element method (FEM) for more than 50 years despite the physical inadequacy of the spectrum of equivalent nodal loads.In recent years, the library of serendipity finite elements has been significantly replen-ished with non-standard (alternative) models. The reasons for the inadequacy of the spectrum were identified and "recipes" were proposed to eliminate this shortcoming of standard serendipity models. New approaches to modeling bases with the help of hierarchical forms force to abandon conoids - linear surfaces that are associated with intermediate nodes of standard elements. According to the authors, these Catalan surfaces (1843) are insufficiently studied and deserve the attention of modern researchers. Therefore, research is being conducted today, and it is not necessary to give up conoids. The paper shows how by compressing the surface of the conoid it is possible to obtain a mathematically sound and physically adequate spectrum of nodal loads. It is interesting that such capabilities are embedded in trigonometric functions, the popularity of which in the FEM is growing steadily.The purpose of the research is to constructively prove the existence of mathematically substantiated and (most importantly) physically adequate models of serendipity elements Q8 with the help of trigonometric bases.Trigonometric models of the finite element Q8 once again confirmed that serendipity elements are an inexhaustible source of important and interesting information. It should be noted that today it is not necessary to give up conoids for the sake of physical adequacy of the model. Conoids are also of "historical" importance to FEM. The first bases of serendipity FEs were constructed from conoids (1968).Taylor's elegant method (1972) is also based on conoids. New results show that trigo-nometric bases are able to preserve conoids and ensure the physical adequacy of the models.

Study on the finite element method of Hamiltonian system with chaos

2020 ◽  
Vol 31 (11) ◽  
pp. 2050165
Author(s):  
Qiong Tang ◽  
YangFan Liu ◽  
Yujun Zheng ◽  
ChengJie Xu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Conservative System ◽  
High Accuracy ◽  
Symplectic Method ◽  
The Finite Element Method ◽  
Kam Tori ◽  
Hamiltonian Chaos ◽  
Element Method

By comparing with symplectic different methods, the quadratic element is an approximately symplectic method which can keep high accuracy approximate of symplectic structure for Hamiltonian chaos, and it is also energy conservative when there have chaos phenomenon. We use the quadratic finite element method to solve the H[Formula: see text]non–Heiles system, and this method was never used before. Combining with Poincar[Formula: see text] section, when we increase the energy of the systems, KAM tori are broken and the motion from regular to chaotic. Without chaos, three kinds of methods to calculate the Poincar[Formula: see text] section point numbers are the same, and the numbers are different with chaos. In long-term calculation, the finite element method can better keep dynamic characteristics of conservative system with chaotic motion.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

Sign in / Sign up

Export Citation Format

Share Document