To predict the consequences of large-scale explosions, it is desirable to understand the response of various industrial and civil structures to blast loading. In the absence of full-scale trials on such structures, and with limited data available in the literature in this regard, emphasis is often placed on modelling to investigate problems of this type. In order for confidence to be placed in analysis results, it is therefore important that adequate validation is performed. A recent investigation into the response of storage tanks employed such an approach, whereby simulations were undertaken at full-scale and validated using scaled experiments. The numerical study was undertaken to investigate the sensitivity of response of storage tanks to the following factors: geometry, fill level and loading. Tank geometries were based on typical standards of design and variations in overall diameter and panel thicknesses were considered. Three tank fill levels were investigated: full, half full and empty, and a range of stand-off and charge height combinations were assessed. Several key damage mechanisms were identified, influenced primarily by fill level. In support of this study, a series of scaled tests was conducted. These tests were used to confirm the damage mechanisms identified from the modelling and provide quantitative validation data. Miniature tanks were manufactured to represent the main design features of the full-scale tanks and placed at two pertinent scaled stand-off distances from a scaled high explosive charge suspended at one scaled charge height. Tests were repeated with the tanks filled to the three levels previously analysed. High speed video was deployed to capture the dynamic response of the tanks and 3D scanning was employed to measure the geometries of the tanks pre- and post-test. Additionally, pressure gauges were fielded to record both free-field pressures as well as pressures across rigid representations of the tanks. Output from simulations of the scaled tests, undertaken prior to the trial to aid trial design, was compared with equivalent experimental results in terms of free-field pressure, tank surface pressure, tank dynamic response and final tank deformation. The previously identified damage mechanisms were replicated in the tests, and good agreement was demonstrated between numerical and physical results. An outline of the initial numerical study, a description of the experimental programme and an overview of the subsequent validation exercise will be presented and discussed.
|Authors||Rogers. A Cannon. L Newman. J Metcalfe. C Dimech. A|
|Date||17th May 2023|