scholarly journals Numerical Investigation of Oleo-Pneumatic Shock Absorber: Setup and Validation

2021 ◽  
Author(s):  
A. Al-Shabab ◽  
D. Vitlaris ◽  
Z. Lin ◽  
B. Grenko ◽  
P. Tsoutsanis ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Shock Absorber ◽  
Pneumatic Shock

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.

Operational processes in a dual-chamber pneumatic shock absorber with rapid switching

2009 ◽  
Vol 29 (10) ◽  
pp. 974-978 ◽  
Author(s):  
R. N. Khamitov ◽  
G. S. Aver’yanov ◽  
A. B. Korchagin
Keyword(s):  
Shock Absorber ◽  
Dual Chamber ◽  
Rapid Switching ◽  
Operational Processes ◽  
Pneumatic Shock

Characterization of a piezoelectric valve for an adaptive pneumatic shock absorber

2013 ◽  
Vol 22 (12) ◽  
pp. 125011 ◽  
Author(s):  
Grzegorz Mikułowski ◽  
Rafał Wiszowaty ◽  
Jan Holnicki-Szulc
Keyword(s):  
Shock Absorber ◽  
Pneumatic Shock

Effect of air chamber and oil properties on damping characteristics of single-tube pneumatic shock absorber

2018 ◽  
Vol 9 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Hongtuo Liu ◽  
Fangwei Xie ◽  
Kai Zhang ◽  
Xinxing Zhang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Initial Pressure ◽  
Structure Design ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Content Type ◽  
Single Tube ◽  
Damping Characteristics ◽  
Air Chamber ◽  
Pneumatic Shock

Purpose The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle suspension. The purpose of this paper is to quantitatively study the relationship between damping characteristics and air chamber and oil properties in single-tube pneumatic shock absorber. Design/methodology/approach Combined with the principle of fluid dynamics and hydraulic transmission technology, the rebound stroke and compression stroke mathematical models, and damping characteristics simulation model are established to investigate the effect of the air chamber and oil property on damping characteristics. Findings Research results show that the initial pressure of the air chamber is the key parameter which influences the damping characteristics of the shock absorber. The change of the initial pressure has more impact on damping force, and less impact on the speed characteristic; the initial volume of the air chamber almost has no effect on the damping characteristics. The density and viscosity of the oil have certain influence on the damping characteristics. Therefore, selecting suitable damping oil is very important. Originality/value Using Matlab/Simulink software to build simulation models, its results are very accurate. The conclusions can provide a theoretical reference for the structure design of a single-tube pneumatic shock absorber.

Comprehensive design of an oleo-pneumatic nose landing gear strut

2020 ◽  
pp. 095441002097937
Author(s):  
Muhammad Ayaz Ahmad ◽  
Syed Irtiza Ali Shah ◽  
Taimur Ali Shams ◽  
Ali Javed ◽  
Syed Tauqeer ul Islam Rizvi
Keyword(s):  
Shock Absorber ◽  
Structural Integrity ◽  
Impact Force ◽  
Landing Gear ◽  
Maximum Pressure ◽  
Element Analysis ◽  
Stroke Length ◽  
Forcing Function ◽  
Design Cycle ◽  
Pneumatic Shock

A comprehensive design cycle of a nose landing gear strut having an oleo-pneumatic shock absorber for a lightweight aircraft is proposed. Design and analysis of a retractable nose landing gear according to Airworthiness Standards FAA FAR Part 23 have been carried out. This research is focused on mathematical modeling of an oleo-pneumatic strut with an analytical solution of design variables at static and dynamic loading conditions. The variation of spring and damping characteristics of an oleo-pneumatic shock absorber with the stroke length is also presented. Feasibility of equivalent mechanical spring and damper along with comparison of pneumatic as air spring and oleo as hydraulic damper is studied. Numerical integration technique was used to solve the dynamic model of an oleo-pneumatic strut with forcing function of an impact force during touch down scenario. Energy conservation principle was used to determine height required for drop tests. Parametric study of anteversion angle within the constraints of ground clearance and volume in the fuselage determined an optimized angle of nose landing gear strut. Based on the maximum pressure and impact force encountered during landing, the hydraulic cylinder and piston design was finalized. In order to validate the proposed design cycle for preliminary phase, a structural integrity of cylinder and piston assembly was carried out using finite element analysis. Deformation, maximum stresses and factor of safety validated the proposed design cycle of a nose landing gear strut specific to a general aviation aircraft having all up mass of 1600 Kg.

scholarly journals Design and technological provision of wear resistance of elastomer surface of rubber-cord casings of damping devices

2021 ◽  
pp. 25-28
Author(s):  
V. G. Churankin ◽  
◽  
A. V. Lyamtsev ◽  
V. V. Derkach ◽  
◽  
...  
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Shock Absorber ◽  
Sliding Friction ◽  
Rolling Friction ◽  
Solid Base ◽  
Cover Layer ◽  
Deformation Component ◽  
Main Factors ◽  
Pneumatic Shock

Two main factors are considered that determining the friction between non-lubricated surfaces of an elastomer and a solid base during their relative motion. The first one is adhesion in the areas of real (actual) catalysis and the second factor is the deformation component, which is due to the delay of recovery of the elastomer after the irregularity is introduced and it is called the hysteresis component of friction. One of the main problems of increasing the resource of pneumatic dampers is minimizing the wear of the covering layer of the rubber-cord casing (RCC). The wear of the RCC is due to the fact that sliding friction occurs in the process of contact between the metal surface and the surface of the RCC, as a result of which the cover layer of the RCC (in some cases with the first cord layer) wears out, depending on the chemical composition of the rubber and the features of the operation of the pneumatic shock absorber. In order to minimize the wear of rubber, it is proposed to change the design of the pneumatic damper so that rolling friction dominates in the contact between the surfaces of rubber and metal

scholarly journals The study of the elastic characteristics of the new hydro-pneumatic shock absorber

2019 ◽  
Vol 16 (5) ◽  
pp. 260-269
Author(s):  
S. V. Repin ◽  
◽  
V. N. Dobromirov ◽  
D. S. Orlov ◽  
A. A. Kapustin ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Pneumatic Shock ◽  
Elastic Characteristics
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