Equivalent scaling method on the dynamic response of box-shaped structures under internal blast

Abstract Scaled-down experiments are one of the main approaches to represent the dynamic response and damage characteristics of full-scale prototype. While, it is well known that structures subjected to dynamic loads do not follow the usual scaling laws due to the size effects and strain rate sensitivity. The present study proposes a new procedure to equivalent scale the dynamic response of steel box structures subjected to internal blast loading. The present equivalent scaling method based on a new dimensionless number and considered the influence of both the size effects of structural dimension and the strain rate sensitivity on material resistance. This method also has an advantage of convenient engineering application. Moreover, two field tests designed according to the present scaling method were conducted to examine the effective of this method. The experimental results show that the smaller scale specimen presents similar damage mode and features with the larger scale one according to the comparison of the test results. In addition, discussions on the similarity of internal blast load and on the larger scale scaling were conducted through numerical simulations. The numerical results show that the similarity of the explosive pressure load inside the structure is related to the complexity of the structure. The difference of the pressure peaks exceeds 10% at the box corner when according to Hopkinson scaling law. The deformation results show that the scaling is more perfectly when the present scaling method is applied.