shock absorbers
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Mechatronics ◽  
2022 ◽  
Vol 81 ◽  
pp. 102701
Author(s):  
Marco Miraglia ◽  
Michael Tannous ◽  
Francesco Inglese ◽  
Birgit Brämer ◽  
Mario Milazzo ◽  
...  

2022 ◽  
Vol 2159 (1) ◽  
pp. 012007
Author(s):  
N Balaguera Medina ◽  
M A Atuesta ◽  
O A Nieto ◽  
P A Ospina Henao

Abstract The fixed-wall rectangular cavity flow problem is a classic problem that has been studied since the beginning of computational fluid mechanics. The present work aims to provide a numerical and computational solution of the Navier-Stokes equations using the finite difference method, applied to model the problem of a magnetorheological fluid in a rectangular cavity with a fixed wall in shock absorbers devices, used in civil structures that use energy dissipators.


2022 ◽  
Vol 2160 (1) ◽  
pp. 012075
Author(s):  
Youshan Hou ◽  
Yong Yang ◽  
Zhongtian Xie

Abstract With the development of technology, modular independent suspension technology has been widely applied on high-movement off-road platforms in the developed world because of the characteristics of offline assembly and full-body lifting. At the same time, after the breakthrough of key techniques such as the stiffness spiral springs, the high dissipation of the shock absorbers, the lightweight of double-wishbone steering mechanism and the non-maintenance bearing, the ability to carry the off-road mobility and armor protection of the military vehicles have been significantly increased. In this case, the application of the modular independent suspension and its current state around the world was explained, that the development of this technology is of great significance to the off-road maneuvering of our military equipment was also represented in this paper.


2021 ◽  
Vol 28 (3) ◽  
pp. 392-398
Author(s):  
Galina Shaidurova ◽  
Oleg Milman ◽  
Aleksey Kiryukhin ◽  
Aleksandr Shaidurov

Thin-layer rubber-metal elements have been widely used in various fields of technology, including helicopter construction, support parts for bridges, shock absorbers in industrial and civil construction. Their work reliability is determined by the design and technological performance features, which require experimental testing and parametric optimization. The article presents the samples and basic models testing results which were aimed at increasing the strength indicators stability of the adhesive ``rubber-metal'' joints and ensuring the failure-free operation of a rubber-metal product in the structure of a pipeline vibration-isolating compensator.


Author(s):  
A. Ozulu ◽  
B. Lyubarsky

The article considers the issue of the system of the running gear of a high-speed electric train with a body inclination and the system of oscillation recovery. The authors considered the main suspension systems of the electric train body, which are currently used. The main problems of these suspension systems were put forward. Attention is paid to the use of air-spring suspension. The pipe suspension of the VL80 electric locomotive and the construction of the trolley itself are considered. The basic criteria of an estimation of efficiency of perspective electromechanical shock-absorbers on which the comparative characteristic is carried out are defined. The article describes a promising electromechanical shock absorber based on a synchronous linear motor, which can provide both body tilt and damping and recovery of oscillations. The functional scheme of control of two synchronous linear motors which are established on one cart is considered. The operation of the control system of synchronous linear motors is described. The design of a linear DC motor with permanent magnets is described. The functional control scheme of two linear DC motors with permanent magnets is considered. The design of the electromechanical shock-absorber of the Bose company is resulted. The comparative characteristic of three perspective electromechanical shock-absorbers on six criteria is carried out. Conclusions are made and an electromechanical shock absorber is selected, which provides the basic needs of rolling stock.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7639
Author(s):  
Carina Emminger ◽  
Umut D. Çakmak ◽  
Rene Preuer ◽  
Ingrid Graz ◽  
Zoltán Major

Dampers provide safety by controlling unwanted motion that is caused due to the conversion of mechanical work into another form of energy (e.g., heat). State-of-the-art materials are elastomers and include thermoplastic elastomers. For the polymer-appropriate replacement of multi-component shock absorbers comprising mounts, rods, hydraulic fluids, pneumatic devices, or electro-magnetic devices, among others, in-depth insights into the mechanical characteristics of damper materials are required. The ultimate objective is to reduce complexity by utilizing inherent material damping rather than structural (multi-component) damping properties. The objective of this work was to compare the damping behavior of different elastomeric materials including thermoplastic poly(urethane) (TPU) and silicone rubber blends (mixtures of different poly(dimethylsiloxane) (PDMS)). Therefore, the materials were hyper- and viscoelastic characterized, a finite element calculation of a ball drop test was performed, and for validation, the rebound resilience was measured experimentally. The results revealed that the material parameter determination methodology is reliable, and the data that were applied for simulation led to realistic predictions. Interestingly, the rebound resilience of the mixture of soft and hard PDMS (50:50) wt% was the highest, and the lowest values were measured for TPU.


2021 ◽  
pp. 123-144
Author(s):  
Anna Rosińska ◽  
Elizabeth Pellerito

AbstractDuring the current global pandemic, when the family or household has been considered the most basic unit of quarantine, the role of the domestic worker – someone who by definition crosses the threshold and enters the space of the home – became problematised quickly. These workers’ ‘outsider’ status – transgressing the boundaries not just of the physical household space, but often also of race, immigration status, and class – has meant that some household workers were more readily regarded as disease vectors who were too risky to allow into the home and let go with little or no warning. In the United States, many of the federal and state relief bills responding to the pandemic continue to exclude the sector or undocumented immigrant workers or both from accessing relief measures. Drawing on an online ethnography of organisations and policy reviews, we analyse the multilevel response of domestic workers’ organisations to address the crisis at both the federal and local levels, with focus on the state of Massachusetts. This chapter tackles the variety of ways in which worker centres in the United States have been at the frontline of the response to domestic workers’ needs, addressing a gap in mainstream and otherwise insufficient relief measures provided by the government. Because of these gaps and the sheer level of need faced by these workers and their families, these centres did what they were prepared to do: continue the service provision, education, organising, and advocacy efforts while expanding their efforts in each of these areas of work.


2021 ◽  
Vol 2021 (4) ◽  
pp. 57-64
Author(s):  
Аnastasiya А. КОNОN ◽  

Objective: To outline the theoretical and methodological foundations of the railway track oscillation frequency analysis. To justify the need to assess the level of vibrodynamic impact of rolling stock on the elements of the track superstructure and the roadbed. To provide a methodology for calculating the oscillation parameters. To evaluate the effectiveness of the use of shock-absorbing elements. Methods: The modeling of the oscillatory process of the railway track elements and the analysis of physical models of oscillations were used. Results: The applicability of assessing the level of vibrodynamic impact of rolling stock on the elements of the track superstructure and the roadbed has been confirmed. A physical model of the vibrodynamic force impact of railway rolling stock and the responses of track infrastructure elements is described. The procedure for calculating the natural frequencies of the elements of the track superstructure and the roadbed and the characteristics of the shock-absorbing elements is given. Practical importance: The presented methods for calculating the natural frequencies of the elements of the track superstructure and the roadbed, as well as the characteristics of resilient shock-absorbing elements – rail shock pads and sleeper pads – make it possible to evaluate the effectiveness of their use to reduce the level of vibrodynamic impacts, to protect against resonance, and ensure the train traffic safety.


Author(s):  
A.E. Belkin ◽  
I.Z. Dashtiev ◽  
E.A. Nikitin

The problem of calculating the system of a cylindrical shaped load transverse damping installed in a coaxial container is considered. This system has several annular belts of insulation with a cyclically symmetric arrangement of shock absorbers along the circumferential direction. A simple dynamic model of one insulation belt formed by polyurethane tunnel-type shock absorbers is investigated. Such shock absorbers have a high energy absorption coefficient and can operate at very high drafts comparable to their height, which is important when the space between the cargo and the container wall is limited. Within the proposed model framework, a harmonic nonlinear analysis of cargo plane oscillations under kinematic excitation coming from the container is considered. A method for reducing a nonlinear cyclically symmetric system with discrete elastic elements, which allows limiting the analysis to the calculation of a vibration isolation system with one degree of freedom, is proposed. Using the harmonic linearization procedure, the amplitude-frequency characteristics of oscillations and plots of vibration isolation coefficients of cargo at different values of excitation amplitude have been obtained. The results are verified by comparing the analytical solution with the results of numerical integration for a non-reduced nonlinear system with two degrees of freedom. The obtained solution allows choosing the vibration isolation belt parameters, in particular the number of shock absorbers and their stiffness, depending on the conditions of kinematic excitation and permissible overload


2021 ◽  
Vol 2131 (4) ◽  
pp. 042056
Author(s):  
A Semenov ◽  
A Smirnov ◽  
M Stepanov ◽  
N Kharaldin ◽  
A Borovkov

Abstract The first part of this paper is devoted to modeling foam taking into account the effect of strain rate on material behavior in the LS-Dyna software package for solving dynamic problems in a wide range of speeds. The MAT_083 material model was used, which analyzes the stress-strain state considering the dependence on the strain rate. The process of adaptation of experimental data for use in the MAT_083 material model is described. The second part of this study touches upon the homogenization of the properties of a shock absorber consisting of SKU-PFL-100 polyurethane (the modeling approach is described in the previous article) and polyurethane foam, the model of which is described in the first part of this paper. Homogenization of the shock absorber is carried out in order to reduce the number of elements in the problem and, accordingly, to improve the calculation performance. The stress-strain curves obtained during the compression of a shock absorber are used in the material MAT_083.


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