Wyniki wyszukiwania - BazTech

1

Risk assessment screening study for fire, explosion and toxicity effects of hydrocarbons stored in a sphere and bullet

Behari N., Noga M.

Journal of KONES

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2017

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Vol. 24, No. 1

47--57

EN

A fast and economical approach was used to assess impact of fires, explosions and toxicity for a LPG gas storage facility using Fire Explosion and Chemical (FEC) Indices, the TNT and TNO multi energy methods, which are part of a process hazard analysis study. The assessment identified high consequence events for radiation, toxicity and overpressure due to catastrophic rupture of spheres and bullets holding LPG. The FEC Indices indicated that further investigation was needed to determine the extent of blast overpressure whereas toxicity was not identified as a high consequence. The TNO method was used to assess overpressure for congested volumes and unconfined vapour cloud explosions for a bullet, whereas the TNT method was used to predict overpressure occurring on a sphere with no congestion. The FEC indices can be used to screen for high consequence events in order to save time and identify the level of risk complexity needed for process equipment, whereas the TNO method can be easily applied when determining safety distances from LPG facilities for various building constructions provided that the degree of congestion is known.

2

Vibration transmissibility behaviour of high order biodynamic models used in vehicle seat design

Behari N., Noga M.

Journal of KONES

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2016

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Vol. 23, No. 3

33--40

EN

The effects of vibration transmissibility using high order biodynamic models of four, five and seven degrees of freedom that can replicate a human body exposed to vibration transmissibility while driving was investigated to identify resonant frequencies associated with injury. It was found that these models address vehicle seat deformities and represent the body hop motion when driving. The five degree of freedom models provided the best results to approximate resonant frequencies associated with the legs, lower torso, spine and whole body vibration at the seat person interface, while the driver's hands were on the steering and was supported with a backrest. The four degree of freedom model excluding the backrest was able to replicate experimental data and a sensitivity analysis of the stiffness and damping parameters indicated that this model was more robust compared to the others, and could predict whole body vibration to accommodate for intra subject variability. Non-linear damping and stiffness properties were noticed for acceleration magnitudes greater than 1g root mean square (rms) and for high order models, which provide greater anatomical description to predict injury in contrast to simple models that have large lumped masses to represent the upper and lower torso. In addition, biodynamic models greater than seven degrees of freedom can be utilised with non-linear stiffness and damping techniques to predict vibration and impedance behaviour for greater number of body ligaments applied to old seats or retrofit seat design applications.

3

Vibration transmissibility behaviour of simple biodynamic models used in vehicle seat design

Behari N., Noga M.

Czasopismo Techniczne. Mechanika

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2016

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Y. 113, iss. 5-M

3--13

EN

Five biodynamic models are investigated to approximate vertical seat vibration transmissibility and mechanical impedance in an effort to reduce experimental time and data collection when designing vehicle seats. The research has found that these biodynamic models of two, three and four degrees of freedom are ideally suited for initial seat design, since whole body vibrations can be easily depicted at approximately 5Hz. Further research is necessary to investigate the resonant frequencies for defined anatomical structures, passenger variability and the use of a backrest support.

PL

W artykule przedstawiono porównanie przenoszenia drgań oraz impedancji mechanicznej dla pięciu prostych modeli biodynamicznych używanych w procesie projektowania foteli dla pojazdów. Przedstawione modele są używane w obliczeniach w celu ograniczenia czasu badań eksperymentalnych i zbierania danych podczas procesu projektowania produktu. Badania wykazały, że porównywane modele o dwóch, trzech i czterech stopniach swobody dają bardzo dobre wyniki na wstępnym etapie projektowania siedzeń. Analiza wykazała, że dalsze prace są potrzebne do zbadania częstotliwości rezonansowych dla określonych cech budowy anatomicznej oraz różnych cech osobniczych dla populacji pasażerów.