Buried high explosive(HE) charges represent a high threat to military vehicles. The detonation of these charges can lead to significant momentum transfer onto vehicles and their occupants. A detailed understanding of ...Buried high explosive(HE) charges represent a high threat to military vehicles. The detonation of these charges can lead to significant momentum transfer onto vehicles and their occupants. A detailed understanding of the physical processes involved in the loading of vehicle structures is necessary for an optimization of effective countermeasures and protection systems. A quantitative description of the local momentum distribution on the vehicle underbody due to the detonation process is of special importance. In the following, a new test setup is presented that allows the experimental determination of the specific impulse distribution. It is based on a ring arrangement where the elements are nested into each other and the velocity of each ring is correlated with the local specific impulse at its position.The momentum transfer to a vehicle depends on a number of influencing factors such as: charge mass,embedding material(e.g. sand, gravel, clay), density, water content, saturation, depth of burial, ground clearance and vehicle shape. The presented technology is applied to quantify the influence of the embedding material(alluvial sand, quartz sand), the burial depth and the water content on the local specific impulse distribution. The obtained data can be used as initial condition for the numerical simulation of occupant safety assessment and as input for empirical modeling of momentum transfer on structures.展开更多
Global effects caused by the detonation of an IED near a military vehicle induce subsequent severe acceleration effects on the vehicle occupants.Two concepts to minimize these global effects were developed,with the he...Global effects caused by the detonation of an IED near a military vehicle induce subsequent severe acceleration effects on the vehicle occupants.Two concepts to minimize these global effects were developed,with the help of a combined method based on a scaled experimental technology and numerical simulations.The first concept consists in the optimization of the vehicle shape to reduce the momentum transfer and thus the occupant loading.Three scaled V-shaped vehicles with different ground clearances were built and compared to a reference vehicle equipped with a flat floor.The second concept,called dynamic impulse compensation(DIC),is based on a momentum compensation technique.The principal possibility of this concept was demonstrated on a scaled vehicle.In addition,the numerical simulations have been performed with generic full size vehicles including dummy models,proving the capability of the DIC technology to reduce the occupant loading.展开更多
采用全概率方法建立非电传爆系统可靠度与传爆环节可靠度的不确定性传递模型,将应用广泛的Sobol全局灵敏度指标推广到非电传爆系统,并采用发展成熟的数值模拟法(Monte Carlo,MC)与单层数值模拟法(Single Monte Carlo,SMC)对指标进行求解...采用全概率方法建立非电传爆系统可靠度与传爆环节可靠度的不确定性传递模型,将应用广泛的Sobol全局灵敏度指标推广到非电传爆系统,并采用发展成熟的数值模拟法(Monte Carlo,MC)与单层数值模拟法(Single Monte Carlo,SMC)对指标进行求解,得到各传爆环节可靠度的重要性排序。根据所得重要性排序,即可有针对性地逐步提高重要传爆环节的可靠度以达到提高系统可靠度的目的。所提指标及方法应用到某非电传爆系统中,证实了其有效性及合理性。展开更多
文摘Buried high explosive(HE) charges represent a high threat to military vehicles. The detonation of these charges can lead to significant momentum transfer onto vehicles and their occupants. A detailed understanding of the physical processes involved in the loading of vehicle structures is necessary for an optimization of effective countermeasures and protection systems. A quantitative description of the local momentum distribution on the vehicle underbody due to the detonation process is of special importance. In the following, a new test setup is presented that allows the experimental determination of the specific impulse distribution. It is based on a ring arrangement where the elements are nested into each other and the velocity of each ring is correlated with the local specific impulse at its position.The momentum transfer to a vehicle depends on a number of influencing factors such as: charge mass,embedding material(e.g. sand, gravel, clay), density, water content, saturation, depth of burial, ground clearance and vehicle shape. The presented technology is applied to quantify the influence of the embedding material(alluvial sand, quartz sand), the burial depth and the water content on the local specific impulse distribution. The obtained data can be used as initial condition for the numerical simulation of occupant safety assessment and as input for empirical modeling of momentum transfer on structures.
基金Herr TRDir K.Husing from the German test range WTD-91 GF-440 in MeppenHerr TRDir K.Neugebauer from BAAINBw
文摘Global effects caused by the detonation of an IED near a military vehicle induce subsequent severe acceleration effects on the vehicle occupants.Two concepts to minimize these global effects were developed,with the help of a combined method based on a scaled experimental technology and numerical simulations.The first concept consists in the optimization of the vehicle shape to reduce the momentum transfer and thus the occupant loading.Three scaled V-shaped vehicles with different ground clearances were built and compared to a reference vehicle equipped with a flat floor.The second concept,called dynamic impulse compensation(DIC),is based on a momentum compensation technique.The principal possibility of this concept was demonstrated on a scaled vehicle.In addition,the numerical simulations have been performed with generic full size vehicles including dummy models,proving the capability of the DIC technology to reduce the occupant loading.
文摘采用全概率方法建立非电传爆系统可靠度与传爆环节可靠度的不确定性传递模型,将应用广泛的Sobol全局灵敏度指标推广到非电传爆系统,并采用发展成熟的数值模拟法(Monte Carlo,MC)与单层数值模拟法(Single Monte Carlo,SMC)对指标进行求解,得到各传爆环节可靠度的重要性排序。根据所得重要性排序,即可有针对性地逐步提高重要传爆环节的可靠度以达到提高系统可靠度的目的。所提指标及方法应用到某非电传爆系统中,证实了其有效性及合理性。
