Numerical Modelling for Strength Estimation of Fragmenting

Introduction: It has been estimated that the total number of meteoroids entering the Earth's atmosphere with masses above 1 kg is about 37000 per year [1]. And approximately 4400 events with mass more than 1 kg strike the Earth every year [1]. Among these im-pactors, those in the mass range ~10 4-3.10 6 kg fragment and form crater fields, with the largest crater resulting from impact of the largest fragment [2]. Fragmented impactors in the mass range over 10 6 – 10 8 kg strike together to form single craters [2]. According to previous estimates [2], eleven 10 5 kg events every 100 years will impact and form a crater field. It is possible to numerically model the formation of many terrestrial crater fields. The solutions, however, are not necessarily unique. A large uncertainty in numerical modelling is in the altitude of breakup, which is related to the yield strength of the meteoroid. Since the cross-range width of a given crater field depends primarily upon the breakup altitude and the down-range length is related to the angle of entry, it is possible to approximately derive these parameters from the terrestrial crater fields. Modelling: Fragmentation of meteoroids by aerodynamic forces is closely connected with their strength – improving models of meteoroid strength is fundamental to understanding of meteoroid fragmentation and to improving our understanding of impact rates at planetary surfaces [2, 3, 4, 5]. Meteorite strength. The comparison of the measured and estimated values of material strength of me-teoroids was performed. We estimated the strength of the main body (1 kg sample) for meteorites and Sumava according to Weibull distribution [6] and using the criterion of the meteoroid breakup [7]. Our estimates are in the same range as the measured values of strength for stony and iron impactors. Maximum strength of the fragmenting body was 4.4·10