Fragmentation can be observed in nature and in everyday life on a wide rangeof length scales and for all kinds of technical applications. Most studies ondynamic failure focus on the behaviour of bulk systems in one, two and threedimensions under impact and explosive loading, showing universal power lawbehaviour of fragment size distribution. However, hardly any studies have beendevoted to fragmentation of shells. We present a detailed experimental andtheoretical study on the fragmentation of closed thin shells of variousmaterials, due to an excess load inside the system and impact with a hard wall.Characteristic fragmentation mechanisms are identified by means of a high speedcamera and fragment shapes and mass distributions are evaluated. Theoreticalrationalisation is given by means of stochastic break-up models and large-scalediscrete element simulations with spherical shell systems under differentextreme loading situations. By this we ex-plain fragment shapes anddistributions and prove a power law for the fragment mass distribution.Satisfactory agreement between experimental findings and nu-merical predictionsof the exponents of the power laws for the fragment shapes is obtained.
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