Study on terminal effects of dense fragment cluster impact on armor plate. Part I: analytical model

The phenomena and the test results of dense fragment cluster impacting armor plate are briefly summarized. The test results indicate that the impulse and the rate of energy deposition on the target and the impacting duration of the fragment cluster are the most important factors, which induces the multi-fragment effects, i.e. synergistic effects, in the impacting process. Meanwhile, they are the characteristic parameters that distinguish the cumulative effects from the additive effects. The analytical methods are employed to investigate the cumulative effects and additive effects caused by the dense fragment cluster. Based on the analysis of the terminal effect of a single fragment, the extrusion-shear damage model of the target impacted by the fragment cluster is developed, and two criteria for the occurrence of the cumulative effect are given and applied to the test analysis. The dimensionless characteristic parameter of the fragment-cluster/target-plate system is also derived.