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On „VZN" damper behaviour at crash

Niculescu A. -I., Jankowski A., Gardulski J.

Journal of KONES

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2010

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Vol. 17, No. 3

321-326

EN

Passive security at crash is an importami problem both for road, and aerial vehicles, first case at horizontal collision and second at vertical one, on landing operation on ground or deck. Both generate human and material injuries, many of them with important negative effects. Damper in bumper a known solution for vehicles protection at crash is realized with different damping devices, from passive elements to actuators. Usually the devices are tuned for 5 km/h crash speed and after collision the passive solutions destroy and must be replaced with other new devices. The solutions using standard shock absorbers and actuators are improper the first dissipating insufficient energy and actuators being more expensive and having a long reaction time so the damping coefficient changing is realized in too low steps. VZN damper concept granted with European Patent EP l 190 184 and Romanian Patent RO l 18546, characterized by progressive damping coefficients with the stroke assures protection at crash, due to its capacity to realize constant damping force without mechanisms and electronics, tuning damping characteristic to this desiderate. The paper presents the differences between the energy must to be dissipated at the same crash speed in horizontal and vertical situation, it being increased at vertical situation, due to the gravity. The same paper evaluates the advantages confers by VZN damper concept comparative to standard one, for both vertical and horizontal collision and concludes the VZN one is better 39% at vertical crash and 25% at horizontal crash comparative to standard one, due to its efficient dissipating system.

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On „VZN" damper behaviour at crash

Niculescu A. I., Jankowski A., Sireteanu T.

Journal of KONES

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2009

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Vol. 16, No. 2

369-374

EN

On landing operation, a brutal contact with the dech or ground, can damage the plane or chopper and hurt the pilot, the crew or the passengers. The paper presents the advantages confer by suspensions using VZN dampers, in this situation. The Romanian self adjustable damper (shock-absorber) concept- VZN-granted with European Patent EU 1190184 and Romanian Patent 118546 assures damping coefficients increasingly by stroke from lower value up to the very high values, giving thus possibility to dissipate a huge energy at all speed regimes high, medium or low. With a convenient damping valve placement and/or dimension, the VZN concept confers possibilities to assure constant decelerationforces, at the human body limit resistance, this solution dissipating the maximal energy ąuantity. The paper indicates solutions for VZN tuning in order to be used to realize constant deceleration at crash and developed one of them for a practical device realizes. The samples where developed so to be realized with components used in actual automotive shock absorber manufacturing, so prototypes being easy to realize. Despite the simulations was realized considering standard damper dissipating energy function piston speed, not sąuare piston speed, the standard damper dissipated 48.5% lower energy comparative to VZN one. This means in the same situation in which VZN damper reduces constant speed from 20 [km/h] to zero, the standard dampers reduces speed up to 11.5[km/h], then collapsing the aerial vehicle.

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A solution for crash and high ground unevenness effect reducing

Niculescu A. I., Alexandru C., Jankowski A.

Journal of KONES

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2008

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Vol. 15, No. 3

389-395

EN

On landing operation, a brutal contact with the deck or ground, or high ground unevenness can damage the plane or chopper and hurt the pilot, the crew or the passengers. The paper presents the advantages confer by suspensions using VZN dampers, in this situation. The Romanian self adjustable damper (shock-absorber) concept-VZN-granted with European Patent EU 1190184 and Romanian Patent 118546 assures damping coefficients increasingly by stroke from lower value up to the very high values, giving thus possibility to dissipate a huge energy at all speed regimes high, medium or low. With a convenient damping valve placement and dimension, the VZN concept confers possibilities to assure constant deceleration forces, at the human body limit resistance, this solution dissipating the maximal energy quantity. The paper evaluates by simulation, the behaviour at vertical crash of aerial vehicles equipped with suspension using VZN and standard dampers. The results given by VZN concept is 200% better than the standard dampers, this new solution giving high possibilities to reduces the risk at landing, a better passengers and body protection, without increased costs. The VZN principle, and damping coefficients, comparative with standard and monroe sensa trac, the kinematic model, speed - time and acceleration evolution for VZN and standard dampers, detail for acceleration - time evolution at VZN and standard dampers acceleration - time evolution for VZN and standard dampers are presented in the paper.

4

Nanotechnology for body protection

Wiśniewski A.

Problemy Techniki Uzbrojenia

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2007

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R. 36, z. 102

7--17

EN

Main aspects of body protection of soldier, like vest, helmet, smart uniform, against small caliber ammunition, in which some elements are made with the use of nanotechnology, are shown. The directions of nanotechnology are concentrated on the following issues: materials, information, biology and energy. Nanomaterials for protection of body soldiers as different types of fibers and nanoparticles, G-Lam nanofibers, fibers and mixture of polymer and nanoparticles in fibers, nanocoated metal, shear thickening fluids and silliputty-type of elastomers in combination with ceramic armour, are mentioned. The different type of technology and measure means in dependence on scale and main parametres of technology nanofibers by electrospinning are explained.