A new theoretical load-distribution model for finite targets subjected to far-field blast waves

Accurately evaluating the blast load on the surface of a finite target structure requires consideration of the clearing effect during the blast wave diffraction process. The calculation of the clearing effect is mostly based on empirical models simplified from experimental data, and its accuracy and scope of application require further verification. In the present study, a new theoretical model of load distribution is proposed, which divides the diffraction process of shock waves and target surfaces into the clearing and equalization phases. By accounting for the differences in the effectiveness of clearing at different locations on the target surface, the model quantifies the surface load distribution. The reliability of the model was verified by comparing data from shock tube experiments and numerical simulations. By comparing the prediction results of the proposed model with those of the Unified Facilities Criteria (UFC) and Hudson models, it is revealed that the proposed model offers better accuracy and applicability. The UFC model is mainly suitable for cases with low peak overpressure, long positive pressure time, and small target size. The Hudson model overestimates the effect of rarefaction wave clearing, resulting in lower prediction accuracy in the later stage of diffraction.