scholarly journals Development of Pneumatic Shock Absorber by Variable Damping

2019 ◽  
Vol 8 (6) ◽  
pp. 1355-1360
Keyword(s):  
Shock Absorber ◽  
Low Cost ◽  
Advanced Technology ◽  
Hydraulic Shock ◽  
Damping Properties ◽  
The Road ◽  
Shock Absorbers ◽  
Variable Damping ◽  
Cost Efficient ◽  
Pneumatic Shock

In commercial models and premium vehicles the damping is varied by sensing the road conditions, driver’s action etc. using ECU’s and damping properties are varied every second. This advanced technology is very costly and complicated for middle class consumers who also need some comfort with low cost. The main issue here is to vary the damping of hydraulic shock absorbers according to the shock to which it is subjected. Thus by sensing the speed of the shock absorber and changing the vibration absorbing capacity of the damper with respect to it will surely be useful. In this project we used a spring valve to sense the speed of the Shock absorber and controlling the valve which is fitted inside the damper. By Variable damping pneumatic shock absorber we can get enough comfort with a simple and cost efficient setup.

Adaptable pneumatic shock absorber

2018 ◽  
Vol 25 (3) ◽  
pp. 711-721 ◽  
Author(s):  
Rami Faraj ◽  
Cezary Graczykowski ◽  
Jan Holnicki-Szulc
Keyword(s):  
Active Control ◽  
Smart Materials ◽  
Shock Absorber ◽  
High Efficiency ◽  
Low Cost ◽  
Electronic System ◽  
Experimental Investigations ◽  
Adaptation Mechanism ◽  
Impact Absorption ◽  
Pneumatic Shock

Recent progress in the field of sensors, actuators, and smart materials allows the construction of more and more efficient controllable pneumatic dampers for shock absorption. Typically, such devices apply online semi-active control techniques, which utilize electromagnetic, piezoelectric, or magnetostrictive valves. As a result, they are characterized by a high efficiency of impact absorption, but simultaneously by a complicated construction and a specialized electronic system. The alternative solutions are semi-passive absorbers that ensure a similar performance by using a much simpler, low-cost construction and a less complicated adaptation mechanism. This paper introduces an adaptable semi-passive single-chamber pneumatic shock absorber, SOFT-DROP, which provides the optimal impact absorption and energy dissipation after a single reconfiguration performed at the beginning of the process. The high effectiveness of the proposed concept is proved in numerical and experimental investigations of the device. Moreover, the proposed semi-passive damper is also compared against already known pneumatic absorbers that utilize semi-active control methods. Ultimately, the device might be used in an airdrop system for delivery of light packages.

The Effects of Fluid and Mechanical Compliance on the Performance of Hydraulic Shock Absorbers

1974 ◽  
Vol 96 (1) ◽  
pp. 101-106 ◽  
Author(s):  
R. W. Mayne
Keyword(s):  
Differential Equations ◽  
Shock Absorber ◽  
Rigid Wall ◽  
Hydraulic Shock ◽  
Orifice Area ◽  
Shock Absorbers ◽  
Constant Area ◽  
Mechanical Compliance ◽  
Hydraulic Shock Absorber ◽  
The Ideal

Dimensionless differential equations are developed which model a hydraulic shock absorber. These equations are solved numerically to determine quantitatively the effects of fluid compressibility and series and parallel springs on the shock absorber operation. Both variable and constant orifice area are considered for a system protecting a mass during impact against a rigid wall. The results show that a finely tuned variable area shock absorber is degraded by the considered forms of compliance. Performance of the constant area shock absorber can be improved by including compliance and, with an appropriate parallel spring, the ideal flat deceleration profile can be obtained without variable orifice area.

The Design of Shock Absorbers for Chemical Equipments

2012 ◽  
Vol 479-481 ◽  
pp. 1283-1287
Author(s):  
Xin Yang ◽  
Xiao Yu Guo ◽  
Ming Liang Ding
Keyword(s):  
Mathematical Model ◽  
Chemical Process ◽  
Shock Absorber ◽  
Low Cost ◽  
Field Validation ◽  
Shock Absorption ◽  
Vibration Problem ◽  
Shock Absorbers ◽  
The Mathematical Model ◽  
Validation Testing

A low cost shock absorber easy to install and tune was designed to solve the vibration problem produced by the compressor in chemical process. By establishing the mathematical model of the dynamic shock absorption, the shock absorber characteristics were analyzed theoretically. The preliminary experiment was conducted on the testing platform to simulate the factory conditions. The shock absorber was then installed on the compressor for the field validation. Testing results agree well with theory and the shock absorber showed good damping performance.

A Kind of Active Control Damping Shock Absorber

2014 ◽  
Vol 620 ◽  
pp. 511-515
Author(s):  
Han Song Yang ◽  
Peng Li ◽  
Li Zhi Gu ◽  
Hui Juan Guo
Keyword(s):  
Active Control ◽  
High Speed ◽  
Shock Absorber ◽  
Mechanical Energy ◽  
Control Variable ◽  
Suspension System ◽  
High Speed Train ◽  
Proportional Valve ◽  
The Road ◽  
Variable Damping

It is the main decrease press type used in high speed train of semi suspension system, as the parameter can not be regulated freely of the semi suspension system, to design a kind of damping shock absorber which with the sensitive and soft system are very important, this system which using of the Electro hydraulic proportional valve to regulation the safety valve, the guide valve and the damping force of shock absorber, get the recycle method of the hydraulic system from inner to outside, and also using the suspension active control variable damping shock absorber to detect the road, this device, in fact, by vibration, which let the valve move relation, turn the mechanical energy into hot and release outside, thus decrease the vibration. To design this variable damping shock absorber ,compared with the semi suspension system ,for it has the connect system and Electro hydraulic proportional valve, and with the road detectors, and various variable parameters, Which let the high speed train more stable and safety, overcome the short of parameter regulation for the semi-automatic suspension system.

Comparisons Between Dynamic Characteristics of Pneumatic, Magnetorheological, and Hydraulic Shock Absorbers

2012 ◽  
Author(s):  
A. M. Salem ◽  
S. Olutunde Oyadiji
Keyword(s):  
Dynamic Characteristics ◽  
Shock Absorber ◽  
Testing Machine ◽  
Mr Damper ◽  
Nonlinear Behaviour ◽  
Hydraulic Shock ◽  
Shock Absorbers ◽  
Wide Range ◽  
Force Velocity ◽  
Force Displacement

The dynamic performance of automotive vehicles is influenced by the suspension system design. Suspensions owing damping elements with a wide range of non-linear behaviour can provide higher mobility and better ride comfort performances. Pneumatic suspensions due to their inherent nonlinear behaviour can provide high mobility performance while suspensions with MR dampers can provide this nonlinearity through the controllable damping force produced by the control of the MR fluid. The pneumatic and MR suspension models are usually developed from experimental force-displacement and force-velocity characteristics. The purpose of this paper is to measure and compare the dynamic characteristics of pneumatic, magnetorheological, and hydraulic shock absorbers. The study is carried out through measuring the characteristics of the different types of dampers at different frequencies and amplitudes using an Electro-Servo Hydraulic (ESH) testing machine. The shock absorber is subjected to sinusoidal excitation of frequency varying from 0 to 10 Hz, and amplitude varying from 0 to 10 mm. In the case of the MR damper, the tests are also done at different current levels of between 0 and 2 amp. The input displacement and acceleration to the shock absorber were measured using an LVDT (Linear Voltage Displacement Transducer) and an accelerometer, respectively while the input velocity was derived from the measured displacement and acceleration. This dual identification of the input velocity was done in order to ensure accurate representation of the velocity. The output force response of the shock absorber was measured by means of a force transducer. The force-displacement and force-velocity characteristics of each shock absorber were subsequently derived from the measured data. The results show the tunability of the MR damper characteristics in comparison to those of the pneumatic and hydraulic dampers.

scholarly journals Experimental Researches on the Dynamic Behavior of the Magnetorheological Damper

2020 ◽  
Author(s):  
Alexandru Dobre
Keyword(s):  
Dynamic Behavior ◽  
Shock Absorber ◽  
Active Suspension ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Passenger Cars ◽  
Damping Force ◽  
The Road ◽  
Shock Absorbers ◽  
Road Profile

In the context of improving the comfort and dynamics of the vehicle, the suspension system has been continuously developed and improved, especially using magnetorheological (MR) shock absorbers. The development of this technology which is relatively new has not been easy. Thus, the first widespread commercial use of MR fluid in a semi-active suspension system was implemented in passenger cars. The magnetorheological shock absorber can combine the comfort with the dynamic driving, because it allows the damping characteristic to be adapted to the road profile. The main objective of the paper is to analyze the dynamic behavior of the magnetorheological shock absorber in the semi-active suspension. In this sense, the author carried out a set of experimental measurements with a damping test bench, specially built and equipped with modern equipment. The results obtained from the experimental determinations show a significantly improved comfort when using a magnetorheological shock absorber, compared to a classic one, by the fact that the magnetorheological shock absorber allows to modify the damping coefficient according to the road conditions, thus maintaining the permanent contact between the tire and the road due to increased damping force.

scholarly journals Diagnostics of the On-Vehicle Shock Absorber Testing

2021 ◽  
Vol 23 (3) ◽  
pp. B178-B186
Author(s):  
Piotr Zdanowicz ◽  
Marek Guzek
Keyword(s):  
Shock Absorber ◽  
Standard Procedure ◽  
Diagnostic Methods ◽  
Test Results ◽  
The Road ◽  
Braking System ◽  
Shock Absorbers ◽  
Angle Method ◽  
Half Power ◽  
Vehicle Testing

The practical problems that usually come up during the on-vehicle testing of motor car shock absorbers have been discussed. Results of example tests carried out to the EUSAMA standard procedure were compared to the test results obtained with using newer methods, i.e. the phase angle method and half power bandwidth method (HPBM). The issue of incompatibility of the typical excitation applied by diagnostic suspension testers with one that often occurs in the road conditions has also been raised. It has also been shown that the wear of shock absorbers may affect the value of braking deceleration of cars with ABS (anti-lock braking system) when moving on uneven ground. The main objective of the work was to assess usefulness and reliability of various diagnostic methods intended for the on-vehicle testing of car shock absorbers.

scholarly journals Slotted shell resilient elements for drilling shock absorbers

2018 ◽  
Vol 73 ◽  
pp. 34 ◽  
Author(s):  
Andrii Velichkovich ◽  
Taras Dalyak ◽  
Ivan Petryk
Keyword(s):  
Cylindrical Shell ◽  
Shock Absorber ◽  
Low Cost ◽  
Hysteresis Loops ◽  
Iterative Algorithms ◽  
Surface Friction ◽  
Energy Criterion ◽  
Geometrical Parameters ◽  
Shock Absorbers ◽  
Vibration Protection

The new design of a resilient element for application in drilling devices of vibration protection is presented. A cylindrical shell with a cut along its generatrix is the peculiarity of the proposed design. The presented resilient element has high loaded and damping properties upon cross dimension hard restriction condition. Besides, the design is simple, technological and low cost. The drilling shock absorber is tested, which is manufactured on the base of several slotted shell resilient elements, operating in parallel manner. A calculation method for slotted shell resilient elements for drilling devices vibration protection is given. This work presents results of slotted cylindrical shell study in conditions of contact interaction with a resilient filler. To provide the research, the authors have developed a verified numerical model of the shell resilient element with a slit and used iterative algorithms for contact problem solving, considering contact surface friction. The stress-strain state of the shell resilient element of the drilling shock absorber was analyzed. Strength of the structure is evaluated by the energy criterion. Hysteresis loops were developed and analyzed for some histories of resilient element cyclic loading. The obtained results make possible rather accurately to take into account effect of the shell and the filler material resilient characteristics, their geometrical parameters and tribological properties on operational characteristics of drilling devices for vibration protection. In its turn, this makes possible to use efficient drilling vibration protection devices, develop vibroinsulator shell designs by the criteria of maximum compliance and required damping level.

Application of the Signal Change Tracking Algorithm in the Hydraulic Shock Absorber Monitoring System

Vestnik MEI ◽  
2021 ◽  
pp. 132-136
Author(s):  
Andrey A. Shilov ◽  
◽  
Aleksey N. Chernyaev ◽  
Keyword(s):  
Monitoring System ◽  
Shock Absorber ◽  
Statistical Processing ◽  
Linear Displacement ◽  
Residual Lifetime ◽  
Hydraulic Shock ◽  
Reactor Plant ◽  
Shock Absorbers ◽  
Displacement Sensors ◽  
Hydraulic Shock Absorber

During nuclear power plant (NPP) operation, the reactor plant main equipment can show displacements when subjected to the effect of various external and internal loads. These displacements are mainly caused by thermal expansion of the metal and seismic loads. To cope with these phenomena, the reactor plant components that are most susceptible to these types of loads are fastened with hydraulic shock absorbers (HSAs) to limit their displacements under the effect of seismic or accident dynamic loads, as well as to ensure thermal displacements in increasing or decreasing the power unit output. For monitoring the HSA operation and indirectly monitoring the displacements of the reactor plant equipment items fastened with hydraulic shock absorbers, the dedicated hydraulic shock absorber monitoring system (HSAMS) is used, which is equipped with linear displacement sensors installed directly on the HSAs. If the displacements go beyond the predetermined limits, the HSAMs algorithms produce an appropriate alarm. The information from the HSAMS is also used by the automated residual lifetime monitoring system (ARLMS) to calculate the steam generator connection pipe displacement criteria parameters. However, during the operation of a number of NPP power units, a problem associated with numerous failures of the HSAMS linear displacement sensors has been faced. These failures manifested themselves in that the sensor signals went beyond the valid range or frozen under the effect of external influencing factors. As a result, the HSAMS and ARLMS operation was complicated by a large number of unreliable measurements and the functions of these systems were not performed in a proper way. To solve this problem, it has been proposed to use an algorithm for tracking signal changes, which can improve the credibility of HSAMS indications by determining unreliable data in the online mode and by performing statistical processing of the already available array of indications.

Vehicle Evaluation During Sustained Solid Axle Tramp: Part 2 — Application of Methodology to Shock Absorber Design Strategies

2015 ◽  
Author(s):  
Paul T. Semones ◽  
H. Alex Roberts ◽  
David A. Renfroe
Keyword(s):  
Rear Axle ◽  
Shock Absorber ◽  
Relative Effect ◽  
Design Strategies ◽  
Passenger Cars ◽  
The Road ◽  
Shock Absorbers ◽  
Design Variables ◽  
Light Trucks ◽  
Rotational Damping

EI Consultants (formerly The Engineering Institute) has, for over a decade, researched and tested methods of mitigating the controllability effects of solid rear axle tramp by optimizing rear axle rotational damping. This optimization has explored the balance between increasing the damping forces of the shock absorbers and increasing the distance between the shock absorbers positioned along the axle. Axle tramp is detrimental to vehicle handling and stability, since the reduction in normal force at the rear tires can lead to a total loss of control situation. On solid rear axles such as those common on SUVs and light trucks, underdamped tramp motion will result in an oversteer characteristic of the vehicle as the rear lateral capacity is compromised due to the tires alternately bouncing out of firm contact with the road surface. In severe cases of axle tramp, the alternating normal forces at both the input tire and the opposite tire will go to zero when each tire fully leaves contact with the ground. EI Consultants has tested numerous SUVs and light trucks and their responses to axle tramp. In order to excite the tramp mode in a sustained fashion for close study of suspension design alternatives, the test methodology utilizes one rear tire with three vulcanized rubber lumps, placed equidistant about the circumference of the tire. Throughout this research, increased effective rotational damping has been repeatedly demonstrated to have a direct relationship to increased controllability. The most recent testing included maneuvers modeled after those recommended in test standard SAE J266: Steady-State Directional Control Characteristics for Passenger Cars and Light Trucks. This testing included multiple shock absorber configurations, and the data was analyzed in multiple domains to provide insight on the effectiveness of various shock absorber design strategies. Several shock absorber design variables were evaluated, with the most significant of these being the lateral distance between the shock mounts along the axle. Other variables that were able to be observed and evaluated in the latest testing included the balance between shock absorber rebound and compression forces, and the relative effect of “staggered” shocks in side-view angle, where one shock is positioned with a rearward angle, and the other shock is positioned with a forward angle. The effectiveness of placing shocks further apart along the length of the axle was unmatched. This paper is the second of two companion papers presenting theory and results on EI Consultants’ most recent axle tramp testing. Where the first paper focused on new understandings of test data analysis theory, this paper will summarize the results of numerous tests and their application to various design strategies for improving solid rear axle tramp damping, with a motivation for enhancing vehicle controllability and highway safety.

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