Structural Intensity Analysis of Bolt Joints in Vibration Environment

2013 ◽  
Vol 475-476 ◽  
pp. 1503-1506
Author(s):  
Yong Juan Zhang ◽  
Guo Ying Zeng ◽  
Deng Feng Zhao
Keyword(s):  
Energy Distribution ◽  
Nonlinear Model ◽  
The State ◽  
Intensity Analysis ◽  
Structural Intensity ◽  
State Identification ◽  
Intensity Vector

A nonlinear model of bolt joints structure in vibration environment is built and Structure Intensity(SI) of it is calculated by FEM as an approach for the state identification of bolts joints structure in vibration environment. The plots of the structure intensity vector under different preforce were obtained and showed the SI changes of bolt joints structure with different preforces.and showed the energy distribution and transmission are different preforces

scholarly journals A method for identifying emergency processes in energy conversion pulse systems

2015 ◽  
Vol 11 (2) ◽  
pp. 74-79
Author(s):  
Dmitry O Tey ◽  
Artem V Gusakov ◽  
Nizam D Keramov
Keyword(s):  
Fourier Transform ◽  
Energy Conversion ◽  
Real Time ◽  
Pulse Energy ◽  
Sampling Rate ◽  
The State ◽  
Main Process ◽  
State Identification ◽  
Conversion System ◽  
Energy Conversion System

The article discusses the problem of identification of the state of the pulse energy conversion system in real time. Investigated a method of reducing the size and the sampling rate of data describing the state of the system wavelet transform, for applying a Fourier transform. Proposed and experimentally tested the algorithm state identification pulse energy conversion system that allows you to determine in real time during the main process of energy conversion

scholarly journals Method for Remote State Identification Snow-Ice Cover by the Ratio of Fresnel Reflection Coefficients

2020 ◽  
Vol 23 (5) ◽  
pp. 46-56
Author(s):  
V. G. Mashkov
Keyword(s):  
Landing Site ◽  
Ice Cover ◽  
The State ◽  
Reflection Coefficients ◽  
Fresnel Reflection ◽  
State Identification ◽  
Key Factor ◽  
Helicopter Landing ◽  
Standard Values ◽  
Remote Identification

Introduction. Currently, the development of safe helicopter landing systems as the most complex and dangerous stage of a flight is one of the priority tasks. A significant number of companies in Russia and abroad are engaged in its solution. Landing on unprepared (unequipped) sites with snow-ice cover may be caused by the need to deliver units, cargo and ammunition in combat conditions, search and rescue operations, evacuations of victims, etc. A key factor for a landing decision is information about the height of snow and about the depth of ice cover. In the paper remote identification of the state of snow-ice cover, excluding the need to present any person (crew member or rescue worker) on a landing site is proposed.Aim. To develop a method for the remote identification of the state of snow-ice cover used to determine the possibility of a helicopter - type aircraft safe landing on a reservoir with snow-ice cover.Materials and methods. Numerical simulation of echo signals Fresnel reflection coefficients polarization ratio was realized in MatLab. Vertical and horizontal polarizations in the range from 25 to 45 degrees were simulated.Results. Intervals of polarization relations correspond to the interval density of snow-ice layers for fixed angles. For example, when θ = 34 for dry snow ρds = 100…500 kg/m3 (ε'ds = 1.162…1.984) – Prm = 5.6915...3.3266, dry firn ρdf = 500…700 kg/m3 (ε'df = 1.984…2.51) – Prm = 3.3266...2.8311, dry ice ρdi = 700…913 kg/m3 (ε'di = 2.51…3.179) – Prm = 2.8311...2.4753. A layer reconstruction inverse problem was solved by indirect determining of complex relative permittivity of each successive underlying layer with 10-2 real part resolution. The identity of the obtained characteristics of snow-ice layers with calculated (standard) values was established.Conclusion. Remote identification of components of a snow-ice cover structure allows one to automate the process of evaluating of landing possibility. Thereby it reduces a decision-making time and increases a level of safety. In contrast to the known methods of identification of the surface layer the identification of multilayer medium layers was carried out.

scholarly journals A Nonlinear-Model-Based Observer for a State-of-Charge Estimation of a Lithium-Ion Battery in Electric Vehicles

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3383 ◽  
Author(s):  
Woo-Yong Kim ◽  
Pyeong-Yeon Lee ◽  
Jonghoon Kim ◽  
Kyung-Soo Kim
Keyword(s):  
Lithium Ion Battery ◽  
Nonlinear Model ◽  
Open Circuit Voltage ◽  
Lithium Ion ◽  
Open Circuit ◽  
The State ◽  
State Of Charge ◽  
Battery Cell ◽  
Model Based ◽  
State Of Charge Estimation

This paper presents a nonlinear-model-based observer for the state of charge estimation of a lithium-ion battery cell that always exhibits a nonlinear relationship between the state of charge and the open-circuit voltage. The proposed nonlinear model for the battery cell and its observer can estimate the state of charge without the linearization technique commonly adopted by previous studies. The proposed method has the following advantages: (1) The observability condition of the proposed nonlinear-model-based observer is derived regardless of the shape of the open circuit voltage curve, and (2) because the terminal voltage is contained in the state vector, the proposed model and its observer are insensitive to sensor noise. A series of experiments using an INR 18650 25R battery cell are performed, and it is shown that the proposed method produces convincing results for the state of charge estimation compared to conventional SOC estimation methods.

Structural Intensity Analysis of Shells Structure under Harmonic Excitation

2010 ◽  
Vol 37-38 ◽  
pp. 1245-1248
Author(s):  
Guo Ying Zeng ◽  
Deng Feng Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rectangular Plate ◽  
Coordinate Transformation ◽  
Harmonic Excitation ◽  
Intensity Analysis ◽  
Structural Intensity ◽  
Mathematical Expressions ◽  
Combined Structure ◽  
Excitation Frequencies

The structural intensity of shells structure was analyzed based on finite element method (FEM) in this paper. The expressions of structural intensity of plate in FEM were given under harmonic excitation. By using coordinate transformation, mathematical expressions of the structural intensity of shells structure in FEM were deduced. The structural intensities of a rectangular plate and combined structure of tube and plate were calculated. The vector plots of structural intensity under different excitation frequencies were analyzed. The results show that the structural intensity under different frequencies are different, the vector plots present directly the distribution and propagation of energy in shells structure.

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