Dynamic response of layered structures subject to blast effects of non-nuclear weaponry
Abstract Protective military structures are typically constructed of massive, monolithic reinforced concrete slabs. This practice is considered necessary in order to protect personnel and/or vital equipment within the structure from the harmful effects of conventional weaponry. Recent studies have indicated, however, that ‘layered structures’ may provide a viable alternative to conventionally hardened structures in certain environments. This paper presents the results of a preliminary numerical study to evaluate the effectiveness of layered structures to resist the blast effects of non-nuclear weaponry.
Abstract Many human operations have created a large population of small orbital debris in near Earth environment. The threat they represent for satellites is a major factor for the preparation of future space missions. Several experiments devoted to the study of this environment, as well as various materials exposed to space, have been retrieved in the past few years. The analysis of the results shows some differences with previous modeling. Comparison with data from LDEF and from EURECA give some insight in the long term evolution of particle size distribution. Chemical identification of particle remnants inside craters is difficult but provides valuable information on the origin of the impactors. Permanent monitoring of environment is obviously needed, especially for the type of orbits where data are presently scarce ie. heliosynchronous and geostationary orbits.