TRANSIENT IMPACTING STRENGTH ANALYSIS OF MOTORCYCLE MODEL

2008 ◽  
Vol 07 (01) ◽  
pp. 75-79
Author(s):  
BAO CHEN ◽  
JIAN OU ◽  
YONG ZHANG
Keyword(s):  
Practical Significance ◽  
Strength Analysis ◽  
Concentrate Mass ◽  
Operating Modes ◽  
Spring Element ◽  
Capacity Theory ◽  
Plate And Shell ◽  
Practical Performance ◽  
Motorcycle Frame ◽  
Element Theory

Considering the disadvantages of analysis method singleness and result differentia in the conventional structural strength analysis of motorcycle, a method concerning transient impacting strength analysis was proposed, which is based on the finite element theory. Then the bearing capacity theory was researched, and three typical operating modes under the acting of transient impacting were confirmed. Under the circumstance of MSC.PATRAN/NASTRAN software, by applying the composite structure of rod, plate and shell which has a high calculation accuracy, the element subdivision of frame is done. The suspension is simulated by spring element, the engine is simulated by concentrate mass element, and then the whole simulation model was developed. The strength of the motorcycle frame was analyzed under the above-mentioned three operating modes. The results of the simulation meet well with the practical performance. Thus, the conclusion shows that this method has more important practical significance.

The method for calculating the probability of brittle destruction of NPP equipment in different operating modes with postulated defectiveness

2021 ◽  
Vol 14 (1) ◽  
pp. 34-39
Author(s):  
D. A. Kuzmin ◽  
A. Yu. Kuz’michevskiy
Keyword(s):  
Fracture Toughness ◽  
Pressure Vessel ◽  
Nuclear Power ◽  
Power Plants ◽  
Reactor Pressure Vessel ◽  
Practical Significance ◽  
Reactor Unit ◽  
Operating Modes ◽  
Brittle Destruction ◽  
Reactor Pressure

The destruction of equipment metal by a brittle fracture mechanism is a probabilistic event at nuclear power plants (NPP). The calculation for resistance to brittle destruction is performed for NPP equipment exposed to neutron irradiation; for example, for a reactor plant such as a water-water energetic reactor (WWER), this is a reactor pressure vessel. The destruction of the reactor pressure vessel leads to a beyond design-basis accident, therefore, the determination of the probability of brittle destruction is an important task. The research method is probabilistic analysis of brittle destruction, which takes into account statistical data on residual defectiveness of equipment, experimental results of equipment fracture toughness and load for the main operating modes of NPP equipment. Residual defectiveness (a set of remaining defects in the equipment material that were not detected by non-destructive testing methods after manufacturing (operation), control and repair of the detected defects) is the most important characteristic of the equipment material that affects its strength and service life. A missed defect of a considerable size admitted into operation can reduce the bearing capacity and reduce the time of safe operation from the nominal design value down to zero; therefore, any forecast of the structure reliability without taking into account residual defectiveness will be incorrect. The application of the developed method is demonstrated on the example of an NPP reactor pressure vessel with a WWER-1000 reactor unit when using the maximum allowable operating loads, in the absence of load dispersion in different operating modes, and taking into account the actual values of the distributions of fracture toughness and residual defectiveness. The practical significance of the developed method lies in the possibility of obtaining values of the actual probability of destruction of NPP equipment in order to determine the reliability of equipment operation, as well as possible reliability margins for their subsequent optimization.

scholarly journals DYNAMIC LOAD REDUCTION DEVICE IN MACHINE DRIVE WITH SPRING AND SELECTION OF ITS PARAMETERS

2021 ◽  
Vol 297 (3) ◽  
pp. 87-93
Author(s):  
Yuri Kovalyov ◽  
◽  
Sergey Pleshko ◽  
Evgeny Lopukhov ◽  
◽  
...  
Keyword(s):  
Dynamic Loads ◽  
Practical Significance ◽  
Process Equipment ◽  
Technological Equipment ◽  
Light Industry ◽  
Torsion Spring ◽  
Operating Modes ◽  
Start Up ◽  
Dynamic Loadings ◽  
Selection Of

The peculiarity of the technological equipment of light industry is the significant dynamic loads that occur during unstable operating modes and is one of the main reasons for reducing the reliability and durability of its operation. The problem of increasing the reliability and durability of their work by reducing the dynamic loads is relevant, because the known means of reducing the dynamic loads in the drive of machines can not always be used in light industry machines. Therefore, when designing light industry equipment, first of all, attention should be paid to reducing the dynamic loads in the drive and preventing accidents. The paper considers the feasibility of using a device with a torsion spring to reduce the dynamic loads in the drive of process equipment, check its performance and develop a method for selecting rational parameters. In the course of work modern methods of researches of mechanical systems are used for the purpose of an estimation of expediency of use of the device with a torsion spring for reduction of starting dynamic loadings in the drive of machine. On the basis of the analysis of features of work of the technological equipment of light industry the expediency of use in the drive of cars of the gear safety coupling with a torsion spring is established. A new design of the device is proposed to reduce the dynamic loads that occur during machine start-up. Unlike the known devices, the proposed device is made in the form of a toothed safety clutch with a torsion spring, which simplifies its design and increases efficiency. The use of a cylindrical torsion spring as an elastic element, which connects the half-clutch to the flange on which the satellite gears are mounted, prevents overloading of the drive and the choice of rational rigidity of the device depending on the change of operation, which increases its durability and expands performance. The method of checking the efficiency of the device for reducing dynamic loads and selecting its rational parameters is presented. The scientific novelty is the development of scientific bases and engineering methods of designing devices to reduce dynamic loads in the drive of technological equipment. The practical significance lies in the development of a new design of the device to reduce the dynamic loads in the drive of machines and the engineering method of choosing its rational parameters.

Numerical Simulation of Multi-Physics Processes in Nuclear System Based on Galerkin Finite Element Method

2020 ◽  
Author(s):  
Baoxin Yuan ◽  
Wankui Yang ◽  
Songbao Zhang ◽  
Bin Zhong ◽  
Junxia Wei ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Source ◽  
Neutron Field ◽  
Practical Significance ◽  
Nuclear System ◽  
Governing Equations ◽  
Galerkin Finite Element ◽  
Calculation Results ◽  
Element Theory

Abstract It is of practical significance to analyze the multi-physics process of nuclear system, which includes neutronics, heat transfer and thermoelasticity. Fission reaction is the heat source in system, the heat source will affect the distribution of temperature field, which will lead to the change of strain. Strain in turn will affect the distribution of neutron field. Therefore, it is necessary to analyze the distribution of neutron flux, temperature and strain in system. Three aspects of work have been carried out: 1) Based on Galerkin finite element theory, the governing equations of neutronics, heat transfer and thermoelasticity are established; 2) The multi-physics analysis code is developed; 3) The calculation results are analyzed and discussed.

GEOMETRICALLY NONLINEAR STABILITY ANALYSIS OF SHELLS USING GENERALIZED CONFORMING SHALLOW SHELL ELEMENT

2001 ◽  
Vol 01 (03) ◽  
pp. 313-332 ◽  
Author(s):  
JIANHENG SUN ◽  
ZHIFEI LONG ◽  
YUQIU LONG ◽  
CHUNSHENG ZHANG
Keyword(s):  
Degrees Of Freedom ◽  
Shallow Shell ◽  
Shell Element ◽  
Linear Analysis ◽  
Continuity Condition ◽  
Body Motion ◽  
Geometrically Nonlinear ◽  
Nonlinear Stability Analysis ◽  
Plate And Shell ◽  
Element Theory

A generalized conforming finite element theory was presented to satisfy the C1 continuity condition for plate and shell element. The effectiveness of the theory in the linear analysis has been proved. This paper discusses the membrane locking phenomenon of shallow shell element based on the satisfaction of the requirement of rigid body motion, and a technique is developed to eliminate the membrane locking phenomenon. Accordingly a geometrically nonlinear generalized conforming rectangular shallow shell element with tangential degrees of freedom of midpoints of sides is formulated. Nonlinear numerical analysis of shell stability shows that the element exhibits high precision and fast convergence characteristics.

scholarly journals The application of vibrational-rotational operation mode in vibratory drive

2020 ◽  
pp. 314-323
Author(s):  
L. A. Payuk ◽  
N. A. Voronina ◽  
I. A. Rozayev ◽  
Anara Daukenovna Umurzakova ◽  
Askar Tokishevich Zhumagazhinov
Keyword(s):  
Mathematical Model ◽  
Induction Motor ◽  
Operation Mode ◽  
Practical Significance ◽  
Dynamic Parameters ◽  
Operational Mode ◽  
Flux Linkage ◽  
Rotational Mode ◽  
Ac Drives ◽  
Operating Modes

In this paper an analysis of the resultant flux linkage vector ψ0 of double-way feed motor (DFM) ​​in the vibrational-rotational mode is shown. It is used for vibration-based diagnostics of various equipment with AC drives. In the case of using DFM in the vibrational-rotational mode the accuracy of motion law implementation is higher than using the standart induction motor. The results of research obtained with the help of a mathematical model of the DFM that allows to explore the special operating modes such as oscillating, polyharmonical, vibrational-rotational and creeping speed ones. The urgency of DFM operational mode and its practical significance as a method of control for vibration-based diagnostics systems are also given herein. The influence of the load parameters on the dynamic parameters of the executive vibratory drive is shown.

scholarly journals Method for estimating the spectrum density of the resistance moment on the working body of a peat milling unit

2020 ◽  
Vol 241 ◽  
pp. 58
Author(s):  
K. Fomin
Keyword(s):  
Spectral Density ◽  
Operating Conditions ◽  
Design Stage ◽  
Strength Analysis ◽  
Operating Modes ◽  
Milling Machines ◽  
Resistance Moment ◽  
Spectrum Density ◽  
The Moment ◽  
Moment Of Resistance

The main source of dynamic loads in the drive elements and the design of the peat milling unit is the working body. The forces of external resistance arising in the process of performing a technological operation are sharply variable, random in nature. The article proposes a model of formation of the moment of resistance on the mill when interacting with peat. The case when there are several cutting planes with the same radius at the ends of the cutting elements is considered. When developing the model, it was taken into account that the operating conditions of the knives, determined by the type of cutting (blocked, semi-blocked, etc.), their width and type in each cutting plane can vary.Factors that determine the nature of loading, such as the frequency of interaction of the cutting elements with the fallow and the randomness of the operating conditions of the unit, lead to the presentation of the loads in the form of a sequence of pulses with random parameters. Expressions are obtained for determining the spectral density of the moment of resistance on the mill at the design stage, taking into account its design, operating modes, physico-mechanical properties of peat and their probabilistic characteristics.To illustrate the application of the developed approaches, a technique is presented for determining the spectral density of the moment on the working body of deep milling machines and in their drive elements based on a linear model. An example of calculation is given, and the obtained expressions are verified on the basis of experimental data.The probabilistic characteristics of the loads on the mill serve as initial information for the dynamic analysis of the drive system and the design of the unit, its strength analysis, the selection of optimal parameters and operating modes. 

scholarly journals IMPROVEMENT OF METAL BRIDGE ROADWAY STRUCTURE DEPENDING ON DECK PAVEMENT OPERATING BEHAVIOR

2020 ◽  
Vol 22 (2) ◽  
pp. 174-184
Author(s):  
S. Yu. Polyakov
Keyword(s):  
Fatigue Strength ◽  
Service Life ◽  
Stress Level ◽  
Design Method ◽  
Practical Significance ◽  
Strength Analysis ◽  
Computation Method ◽  
Heavy Load ◽  
Practical Applications ◽  
Bridge Superstructures

The bridge pavement perceives millions of live load application cycles during its service life. Therefore, fatigue defects often occur in asphalt. These defects are associated with insufficient fatigue strength, for example, top-bottom cracks that appear after several years of operation and grow from top to bottom. These cracks cause more serious defects. It is necessary to prevent their occurrence.The purpose of this article is to increase the asphalt service life on bridge superstructures by developing the pavement design method. To achieve this goal, the pavement fatigue strength is analyzed. Firstly, asphalt stress-strain state is determined under the heavy load. Secondly, a safe stress level is prescribed. At this stress level, asphalt receives the required load cycles without failure. A significant increase in the orthotropic steel deck stiffness is determined to be necessary.The practical significance is the analysis of several ways to reduce asphalt stresses to the required level. The effectiveness of these methods is evaluated. New problems are identified that will enable the development of the computation method for the bridge pavement and its practical applications.The originally includes the pavement fatigue strength analysis on road bridges with regard to the temperature influence on the asphalt fatigue strength. 

Study on Fiber Element Used for Simulate SRC Component

2012 ◽  
Vol 174-177 ◽  
pp. 1285-1289
Author(s):  
Shan Suo Zheng ◽  
Wei Wang ◽  
Pi Ji Hou ◽  
Ming Xie
Keyword(s):  
Bearing Capacity ◽  
Ultimate Load ◽  
Practical Significance ◽  
Failure Model ◽  
Bond Slip ◽  
Steel Material ◽  
Fiber Element ◽  
Set Up ◽  
Element Theory ◽  
Finite Method

The existed research shows that when SRC component is under stress, there is bond-slip happened between shape steel and concrete. And the bond-slip have a certain influence on the bearing capacity of SRC component, when component is loaded to ultimate load, the bearing capacity descends quickly because of the effect of bond-slip between shape steel and concrete. Finite method of fiber finite element is a useful way to simulate this kind of composite components, but it ignores the behavior of bond-slip between shape steel and concrete. So building a bond-slip formula for fiber element to simulate SRC component has a practical significance. It’s not only gets more precisely calculated results, but also make the simulation of failure model close to the practical situation. In this paper, in order to add bond-slip effect into fiber element theory, a formula was set up to adjust stress of steel material, which was based on constitutive equations of our bond-slip tests. The method was programmed in OpenSees and used to simulate tests of SRC frame under cycling load, the simulate results shows that the method suggested in this paper is an effective way to express behavior of bond-slip in SRC component.

scholarly journals The efficiency of the active controlled rectifier operation in the mains voltage distortion mode

2021 ◽  
pp. 30-35
Author(s):  
D. S. Krylov ◽  
O. I. Kholod
Keyword(s):  
Control System ◽  
Control Systems ◽  
Supply Voltage ◽  
Practical Significance ◽  
Supply Network ◽  
Power Supply Voltage ◽  
Software Environment ◽  
Operating Modes ◽  
Active Rectifier ◽  
Vector Control System

Goal. Checking the efficiency of the active rectifier with differences types of control systems in conditions of deep voltage distortions of a three-phase three-wire supply network. Methodology. The authors have used the Matlab/Simulink software environment to create a model of an active rectifier with various types of control systems as part of a frequency electric drive. We performed a series of simulations of the operating modes of an active rectifier with various control systems when the supply voltage is distorted. Results. When the active rectifier is operating in an unregulated mode, the distortions of the current and mains voltage exceed the maximum permissible values. The quality indicators of the mains current and mains voltage are significantly higher than the normally permissible values. In the absence of voltage distortions in the supply network, the operation of the active rectifier can effectively eliminate the distortions of the mains current, regardless of the type of control system of the active rectifier. In conditions of deep distortions of the supply network voltage, the operation of an active rectifier with a vector control system is more efficient than with a parametric control system. Originality. Criteria for determining the quality of consumed electricity at the connection point of the circuit are proposed. Practical significance. Recommendations have been developed for the use of active rectifier control systems when working with a distorted power supply voltage.

Specimen Preparation for Clinical Applications of X-Ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 328-329
Author(s):  
J.D. Shelburne ◽  
G.M. Roomans
Keyword(s):  
Carbon Coating ◽  
Clinical Applications ◽  
Point Of View ◽  
Practical Significance ◽  
Sweat Test ◽  
Specimen Preparation ◽  
Tissue Preparation ◽  
X Ray ◽  
Gallbladder Stones ◽  
Clinical Problems

Proper preparative procedures are a prerequisite for the validity of the results of x-ray microanalysis of biological tissue. Clinical applications of x-ray microanalysis are often concerned with diagnostic problems and the results may have profound practical significance for the patient. From this point of view it is especially important that specimen preparation for clinical applications is carried out correctly.Some clinical problems require very little tissue preparation. Hair, nails, and kidney and gallbladder stones may be examined and analyzed after carbon coating. High levels of zinc or copper in hair may be indicative of dermatological or systemic diseases. Nail clippings may be analyzed (as an alternative to the more conventional sweat test) to confirm a diagnosis of cystic fibrosis. X-ray microanalysis in combination with scanning electron microscopy has been shown to be the most reliable method for the identification of the components of kidney or gallbladder stones.A quantitatively very important clinical application of x-ray microanalysis is the identification and quantification of asbestos and other exogenous particles in lung.

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