Relation between hardness and dynamic flow stress for a range of steel types
conference paper
Engineering models can be a valuable tool for armour design and vulnerability calculations. Often such models use a simplified target material response for the dynamic loading conditions. An example of such a parameter is the so-called dynamic flow strength of the target, Yt. This value can be obtained by fitting to data from ballistic experiments. A major drawback from this approach is that ballistic experiments have to be performed to fit the model before prediction can be made. This paper investigates an alternative approach, where the Yt value is related to the Vickers hardness of the steel material which is much easier measured. To investigate and demonstrate this approach, a variety of ballistic and hardness tests are performed on steel plates with different thicknesses. It is found that the Yt value has a linear relation to the Vickers hardness. Using the estimated Yt value in the engineering model, yields a reasonably accurate prediction of the V50 for EH36 for different thicknesses when compared to experiments. It is further shown that the hardness of EH36 steel depends on the plate thickness, and that a micro-Vickers indentation measurement yields more accurate and consistent measurements than constant material strength value. This former demonstrates the importance to characterise the target material for the correct target thickness. This work contributes to the improvement of engineering models that can be used in the design of ballistic protection for military platforms.
TNO Identifier
1002581
Publisher
TNO
Source title
Light-Weight Armour for Defence & Security LWAG 2024, Rocamadour, France, 10-13 June 2024
Collation
6 p.
Files
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