An approximation procedure of the Axelsson model for quick injury prediction

In risk analysis tools it is desirable to have quick modules for estimating the injury and lethality due to blast. The current injury models however are too cumbersome. Both the Axelsson model and the Stuhmiller model require the input of four full pressure-time curves, which are to be measured with a so-called BTD. Next a full response calculation per load curve must be carried out before the necessary output is available for the injury prediction. TNO has studied the Axelsson model for blast injury prediction in detail and an approximation procedure for the Axelsson model has been developed. With examples it has been shown that the procedure predicts the Axelsson velocity with sufficient accuracy. For quick predictions the procedure is equivalent to the Axelsson model itself, if not even more preferable, as the approximation procedure is less sensitive to small changes in the input. It is therefore more suitable for cases with uncertainties or for rough analyses. The procedure is described in this paper, together with examples to show how the simplified approach compares with the original Axelsson model. The examples also give insight in some typical aspects of the Axelsson model, which one should be aware of when using the model. These typical aspects are discussed