Investigation on similarity laws of cabin structure under internal blast loading

Abstract

Owing to the influence of the strain-rate effect of materials, scale models of cabin structures under internal blast loading do not accurately represent similar the prototypes. In this study, an optimal approximation method for correcting the specific impulse factor is utilized based on a dimensional analysis method. The effects of the strain-rate sensitivity parameters (C and P) on the dynamic similarity of the material used were analyzed according to the Cowper-Symonds constitutive model. A numerical cabin structure model was established according to the experimental background. A comparison of the numerical and experimental results demonstrate that the numerical method and material models are able to utilize the similarity law for the correction of scale models. The prototype and scale models of the cabin structure subjected to the internal explosion were calculated, which indicated that a smaller the scale factor β leads to larger error in the prototype response’ prediction. Based on the analysis of the calculation results following the correction by employing the method proposed in this study, it can be seen that the modified models significantly improve the prediction accuracy of the scaling model to the prototype structure.