scholarly journals Application of Elastic Fastenings of Equipment to Increase Vibration Frequency of the Wagon Body

2021 ◽  
Vol 19 (2) ◽  
pp. 6-12
Author(s):  
R. V. Guchinsky

Improving dynamic performance is a priority when designing new rolling stock. The frequency of natural bending vibrations of the body is one of the most important standardised indicators, a preliminary assessment of which allows obtaining optimal body designs.The objective of the work is to assess the prospects for the use of elastic fastenings of equipment to increase the natural vibration frequency of wagon bodies of suburban electric trains. Calculations were based on the finite element method and block Lanczos method. It is shown that it is advisable to use the rigid area tool and linearly elastic finite elements to calculate the frequencies in the simulation. The main ranges of fastening stiffness are highlighted, where the effect of using elastic supports is different. It is proposed to determine the stiffness of fastenings according to a given vibration frequency of the equipment. When the equipment is rigidly attached, the relative mass of the equipment does not affect the body bending vibration frequency. With elastic fastening, a greater effect can be achieved with a larger relative weight of the equipment. The effect of using resilient mounts increases with heavier equipment located closer to the centre of the body.It is shown that the effect of shear admittance of fastenings on the body vibration frequency is within 1 % and may not be considered in the simulation. In the considered example of a wagon body of a suburban electric train, the use of elastic supports allows an increase in the frequency of oscillations of the body by 3–10 %. 

2021 ◽  
Vol 80 (3) ◽  
pp. 152-159
Author(s):  
R. V. Guchinsky

Finding ways to optimize the body structure is an important point in the design of new electric train cars. Reducing the mass of the body leads to a lightening of the parts of the rolling stock associated with it, a reduction in energy consumption for operation and a decrease in wear in the “wheel — rail”system. Reducing the weight of the body is possible by assigning optimal rigidity to its main load-bearing elements. Increasing the rigidity of the body with a constant mass is also an important task to obtain the standard dynamic properties of the car body.The article presents method for optimizing the body structure based on calculating the value of its first frequency of natural bending vibrations. The calculation was carried out by the finite element method using a simplified beam-shell parametric model. Within the optimization calculations, 3125 working versions of sections of the main load-bearing structural elements with different rigidity were considered — bracing and cross-beams of the frame, inter-window racks and cross-beams of the roof. The sensitivity of the value of the natural vibration frequency to the change in the rigidity of the main bearing elements without taking into account the change in mass is analyzed. It was found that the rigidity of the frame bracing and cross beams has the greatest influence on the frequency value. It is shown that the ratio of the rigidity of the main bearing elements does not remain constant for optimal design options and depends on the design of the body, the target values of its mass and rigidity. When mass is limited, it is possible to choose designs that are characterized by the greatest overall body rigidity and are the most optimal in terms of manufacturability. By limiting the values of natural vibration frequency, it is possible to choose a body structure with the lowest metal mass. The presented approach allows making decisions on body modification based on the required parameters of mass and (or) the frequency of natural bending vibrations. This approach can be used in pre-design studies of the bodies of new passenger rolling stock.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mei Kuihua ◽  
Sun Shengjiang ◽  
Jin Guoqing ◽  
Sun Yamin

The elastic modulus and deadweight of carbon fiber-reinforced polymer (CFRP) cables are different from those of steel cables. Thus, the static and dynamic behaviors of cable-stayed bridges using CFRP cables are different from those of cable-stayed bridges using steel cables. The static and dynamic performances of the two kinds of bridges with a span of 1000 m were studied using the numerical method. The effects of geometric nonlinear factors on static performance of the two kinds of cable-stayed bridges were analyzed. The live load effects and temperature effects of the two cable-stayed bridges were also analyzed. The influences of design parameters, including different structural systems, the numbers of auxiliary piers, and the space arrangement types of cable, on the dynamic performance of the cable-stayed bridge using CFRP cables were also studied. Results demonstrate that sag effect of the CFRP cable is much smaller than that of steel cable. The temperature effects of CFRP cable-stayed bridge are less than those of steel cable-stayed bridge. The vertical bending natural vibration frequency of the CFRP cable-stayed bridge is generally lower than that of steel cable-stayed bridge, whereas the torsional natural vibration frequency of the former is higher than that of the latter.


2012 ◽  
Vol 605-607 ◽  
pp. 1168-1171 ◽  
Author(s):  
Tian Li Chen ◽  
Jing Zeng ◽  
Yao Hui Lu ◽  
Li Min Zhang

In order to research the influence of the flexible car body on the vehicle system dynamic performance and to achieve the reasonable match between high speed and lightweight,it is necessary to build vehicle system dynamic model with the rigid car body replaced by the flexible car body. Due to the lower structure natural vibration frequency of car body, the influence of carbody flexibility on vehicle system dynamic performance is more influential. The influences of structural vibration of car body on vehicle system dynamics performance were studied by finite element analysis (FEA) method and multi-body system (MBS) dynamics theory. Rigid-flexible coupled vehicle system dynamic models were built up and the car body key location’s vibration was analyzed through vibration transmission chain. The results show that the influences of high speed carbody structure vibration on vehicle system dynamics performance are distinguished especially in the domain of car body natural vibration frequency.


Author(s):  
Ivan Alexeyevich Burlakov ◽  
Victor Nickolaevich Kryuchkov ◽  
Irina Vladimirovna Volkova

The article focuses on the intensive anthropogenic impact on the aquatic ecosystems, which makes it necessary to monitor the populations of different fish species. The method of mor-phophysiological indicators was used to study the kidneys of silver bream in different water bodies of the Volga Delta. The morphometric characteristics of the kidneys of silver bream are presented. It is shown that the reactions of organs and body systems are caused by the environmental impact on the living organisms, which results, in particular, in the pathological changes in the fish body. Reactions in the body of fish are the result of a combined effect of environmental factors and natural physiological processes related to feeding, migrations, generative cycles, etc. The detected changes in the organ structure make it possible to assess the impact of the environment on fish. The seasonal and sexual variability of the indices of the mesonephros of silver bream from the Volga Delta is shown. Analysis of the kidneys of fish from two water bodies showed the variability of kidney mass due to the anthropogenic load on the water body, in particular, an increase in the kidney index in silver bream Blicca bjoerkna was registered in the ecosystem with an increased toxic load. It has been stated that the increase in the relative mass of mesonephros was caused by the changes in the organ. Changes were detected both in the intratubular tissue, and in the convoluted tubules and renal capsules. The study helped to find the differences in the relative weight and structure of the kidneys of silver bream, which lives in the water bodies with different anthropogenic load. A real increase of the kidney index was found in fish from the water body with a higher level of anthropogenic impact.


Author(s):  
Dmitriy Dmitrievich Aseinov ◽  
Vyacheslav Mikhailovich Raspopov ◽  
Yulia Valerievna Sergeyeva

The article focuses on the study of changeability of morphological and physiological characteristics of 850 specimens of beluga ( Huso huso ) and sturgeon ( Acipenser gueldenstaedtii ) juveniles obtained at the Ikryaninskiy and Bertyulskiy sturgeon hatcheries in the Astrakhan region. There was determined weight of the body, heart, liver and spleen, as well as the relative mass of these organs - cardiosomatic, hepatosomatic indices and index of a spleen. Sturgeon juveniles were studied within 47-127 days, beluga juveniles within 40-116 days. Certain tendency was noted: cardiosomatic index decreased with aging in both sturgeon and beluga, i.e. the relative weight of the heart in ontogenesis changes inversely to the body weight, which corresponds to literature data. Comparison of the dynamics of the liver relative weight in sturgeon and beluga juveniles showed that it coincides at two segments: maximum raise to 50-60ths day from the birth and a gradual decrease in older juveniles. The value of spleen index in juveniles of both types rose with aging. It was found in the course of the study that the size of internal organs could change, getting smaller under unfavorable factors, in particular, when juveniles suffer from the lack of feeds. In such circumstances the dynamics of developing main internal organs drastically slows down, which reflects on physiological adequacy (quality) of juveniles. Thus, morphological and physiological indicators characterizing the degree of the vitals development can be used not only for characterizing species differences of the investigated group of fish at all stages of ontogenesis, but as important factor for assessing conditions of Russian sturgeons juvenile breeding and the degree of morphological and physiological maturity of the juveniles before releasing into the natural water body.


Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 853
Author(s):  
Dongmei Xu ◽  
Wenzhong Yang ◽  
Xuhui Zhang ◽  
Simiao Yu

An ultrasonic motor as a kind of smart material drive actuator has potential in robots, aerocraft, medical operations, etc. The size of the ultrasonic motor and complex circuit limits the further application of ultrasonic motors. In this paper, a single-phase driven ultrasonic motor using Bending-Bending vibrations is proposed, which has advantages in structure miniaturization and circuit simplification. Hybrid bending vibration modes were used, which were excited by only single-phase voltage. The working principle based on an oblique line trajectory is illustrated. The working bending vibration modes and resonance frequencies of the bending vibration modes were calculated by the finite element method to verify the feasibility of the proposed ultrasonic motor. Additionally, the output performance was evaluated by experiment. This paper provides a single-phase driven ultrasonic motor using Bending-Bending vibrations, which has advantages in structure miniaturization and circuit simplification.


Author(s):  
Yuan Zhou ◽  
Tian Tian ◽  
Xiongfei Yu ◽  
Ran Ren ◽  
Liangcai Zhou ◽  
...  

Author(s):  
Jiazhong Zhang ◽  
Bram de Kraker ◽  
Dick H. van Campen

Abstract An elementary system with gears and excited by unbalance mass has been constructed for analyzing the interaction between torsion and bending vibration in rotor dynamics. For this system, only the interaction caused primarily by unbalance mass has been investigated. The stability and bifurcation characteristics of the system have been studied by numerical computation based on Hopf bifurcation and Floquet theory. The results show that the interaction between torsion and bending vibrations can affect the stability and bifurcation of the unbalance response, in particular the onset speed of instability. In addition to the above, the interaction also affects the steady-state response. To investigate the influence of unbalance mass, the periodic solution and its stability have been studied near the first bending critical speed of the decoupled system. All the results show that the coupling of torsion and bending vibrations can have a significant influence on the nonlinear dynamics of the whole system.


2021 ◽  
Vol 2021 (8) ◽  
pp. 67-76
Author(s):  
Sergey Korshunov ◽  
Aleksandr Skachkov ◽  
Sergey Samoshkin ◽  
Aleksandr Smirnov ◽  
Dmitriy Goncharov

The development of the international trade and the entrance of domestic car manufacturers into international markets required bench equipment development for tests in accordance with the requirements of the European standards. In this connection the purpose of this work is to develop an experimental and methodical basis for the estimation of the strength correspondence of export railway produce to the European standard basis. In the work there is shown a description of the bench developed for static tests of rolling stock for loads corresponding to the European standard basis. In the requirements mentioned there is used a more extended list of loads and combination of efforts and the necessity in the application of longitudinal loads to the elements of the end wall in three levels should be particularly emphasized. On the test bench there are carried out static tests of the car of model 61-4514 for Egyptian national railways and the body of the motor-rail car of model 2853 for the railway infrastructure of Serbia.


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