Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  LS-Dyna
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
In surface mining operation, blasting method has been commonly used and accounted highly for breaking waste rock and mineral. The main goal of the activity is fundamental fragmentation by energy generation due to blasting. However, only 20% to 30% blasting energy is generated to fragment rock. The remain energry is wasted for flyrock, ground vibration, air overpressure, dust and too fine fragmentation. Flyrock in blasting is large risk for surface mines and occupies more than a half of incidents relating to blasting at surface mines, because this is a severe issue and causes negative reaction of the surrounding residients. However, studies on flyrock-phenomenon prediction methods for blasting in Vietnam have been also limited. In the study, simulation analysis method on induce-blasting-induced flyrock experiment using Smoothed Particle Hydrodynamics (SPH) with LS-Dyna software. Two-dimension modelling was built and practically applied for B2 cross section of Mong Son quarry in Yen Bai province. The result showed that the ability of Smoothed Particle Hydrodynamics (SPH) in analysizing flyrock trajectory distance in blasting. By using the modelling with field-site parameters, the researcher monitored flyrock velocity at installed time periods, such as 1.5 second when the flyrocks fly with a maximum distance of 85 m from blasting site and their average velocity of 40 m/s.
PL
W pracy przedstawiono podejście numeryczne do modelowanie zjawiska inicjacji oraz propagacji fali uderzeniowej pochodzącej od wybuchu TNT w aspekcie badań poligonowych. Przedstawiono wyniki analiz numerycznych modeli opracowanych na podstawie badań eksperymentalnych odzwierciedlających warunki badań poligonowych. Symulacje przeprowadzono przy użyciu dwóch algorytmów dostępnych w kodzie obliczeniowym LS-Dyna - podejścia ALE (Arbitrary Lagrangian-Eulerian) oraz funkcji CONWEP. Otrzymane charakterystyki zmiany ciśnienia dla punktów pomiarowych odpowiadających miejscu mocowania czujnika ciśnienia w warunkach poligonowych pozwolą na poprawną walidację badań eksperymentalnych zjawiska wybuchu. Do zrealizowania postawionego zadania wykorzystano oprogramowanie Hypermesh, LS-Prepost oraz LS-Dyna.
EN
The paper presents the results of numerical analyses of models developed based on experimental tests representing the field tests conditions. The paper presents a numerical approach to modelling the phenomenon of initiation and propagation of a wave from TNT explosion in terms of field tests. The simulations were conducted with the use of two algorithms implemented in LS-DYNA code: ALE (Arbitrary Lagrangian-Eulerian) method and CONWEP function. The obtained characteristics of pressure change for measurement points corresponding to the location of pressure sensor fixture in the field tests conditions will allow accurate validation of experimental tests of an explosion phenomenon. Hypermesh programme was applied to accomplish the given task, LS-Prepost to develop a model and analyses the results and LS-Dyna as a solver for conducting the calculations.
PL
W pracy przedstawiono analizę numeryczną testu balistycznego pocisku kalibru 7,92 × 33 przeprowadzoną na podstawie wytycznych norm opracowanych przez niemieckie towarzystwo VPAM. Test balistyczny polegał na penetracji przez pocisk płyty stalowej, wykonanej ze stali Weldox 700E o grubości 8 mm, w zależności od kąta natarcia. Analiza numeryczna dotyczyła weryfikacji literaturowych danych dotyczących kąta natarcia pocisku i skutecznej penetracji płyty stalowej.
EN
This paper presents some ways of modeling the bullet impact in the LS-Dyna. An attempt was made to verify the literature data the angle of impact of the projectile with the effective penetration of steel plate.
EN
This paper presents works associated with the design, experimental tests and numerical analyses of a composite connector, which is a part responsible for increasing the safety of the soldiers. Nowadays researchers more and more often are searching for modern materials, which, as individual components or structures connected with other materials, meet the requirements of global markets. One of the most important branches of industry, which presently is growing increasingly are high technologies accompanying the safety of soldiers who are the passengers of a military vehicle. The proposed solution allows protection of the sensitive parts of body (e.g. legs), as well as the entire body of a soldier from the risks resulting from the impact of a pressure wave coming from explosion on the vehicle in which the soldier travels. A combination of classic materials, such as steel, and modern materials with hyperelastic characteristics might be an alternative to the currently used shock absorbers and dampers. Perspective can be using this assembly as a connector between a seat and the military vehicle body or special plates for protecting the crew’s feet resting on the floor of the vehicle during explosion of a mine or IED. The analysis is conducted using the LS-DYNA explicit code.
PL
W pracy zostały przedstawione wyniki modelowania oraz symulacji numerycznych paneli energochłonnych absorbujących energię pochodzącą od wybuchu. Przedstawiono syntetyczny sposób analizy zagadnienia od opracowania geometrii po przygotowanie modelu numerycznego. Wyniki w postaci sił obciążających charakterystyczne punkty pomiarowe manekina Hybryd III 50th w wersji Fast oraz pozostałe charakterystyki przedstawiono w formie wykresów.
EN
This study presents the results of numerical simulations of an energy absorbing panels as an element increasing the safety of the military vehicle crew. The simulations are made by a finite element method in LS-Dyna. A numerical Hybrid III 50th dummy is used to simulate the tibia axial compressive forces and accelerations. Simulations results are compared with literature data to validate the Hybrid III dummy. Forces and accelerations results are presented in the form of a charts.
EN
Purpose: Whiplash injuries to the cervical spine represent a considerable economic burden on society with medical conditions, in some cases persisting for more than a year. Numerous studies of whiplash injuries have been made for occupant normal seated position, leaving the analysis of neck injuries for out-of-normal positions not well documented. For that purpose, a detailed human cervical spine finite element model was developed. Methods:The analysis was made for four most common occupant seated positions, such as: Normal Position with the torso against the seat back and the head looking straight ahead, Torso Lean forward position with the torso away from the seat back for approximately 10°, Head Flexed position with the head flexed forward approximately 20° from the normal position and HeadFlexed with Torso Lean forward position with the head flexed forward approximately 20° and torso 10° from the normal position. Results: The comparative study included the analysis of capsular ligament deformation and the level of S-curvature of the cervical spine. The developed model predicted that Head Flexed seated position and Head-Flexed with Torso Lean forward seated position are most threatening for upper and lower cervical spine capsular ligament respectively. As for the level of S-curvature, the model predicted that Head-Flexed with Torso Lean forward seated position would be most prone to neck injuries associated with it. Conclusions:This study demonstrated that the occupant seated position has a significant influence on potential whiplash injuries.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.