Investigation on similarity laws of cabin structure for the material distortion correction under internal blast loading: Fid-Bau Portal

Investigation on similarity laws of cabin structure for the material distortion correction under internal blast loading

Qin, Yezhi / Wang, Ying / Wang, Zhi / Yao, Xiongliang

Abstract When the material of the scale model structures differs from that of the prototype, the dynamic response of the structure will be distorted, leading to imperfect similarity. A technique that compensates for this distortion is utilized by applying the best approximation method to correct the thickness scale factor $β_{h}^{*}$ . First, the similarity law of the cabin structure under internal explosion is derived, and the theory of the best approximation method to correct the thickness scale factor is proposed when the scale and the prototype models adopt different materials. Three groups of cabin structures numbered N1-921A-6 mm, N2-Q345-8 mm and N3-Q345-10 mm maintaining the same size ( $β = 1.0$ ) subjected to the internal blast were performed and the corresponding numerical simulations were conducted and compared with experimental results which were in good agreement with the experimental results. The thickness of the cabin structure plate was corrected using the proposed method, and the result of the corrected model precisely agreed with the prototype results. Subsequently, the similarity between the stiffened and the none-stiffened cabin structures made of Q345 steel and the prototype cabin structure made of 921A steel under different scaling factors ( $0.2 < β < 1.0$ ) was analysed. The scale factor $β$ exceeding 0.5 was proposed when using the Q345 scale model to predict the 921A model which shows good and reliable results.

Highlights • The dynamic best approximation method based is applied to correct the thickness plate factor $β_{h}^{*}$ . • The dynamic responses of cabin structure subjected to internal blast load were revealed. • The prediction accuracy of corrected model is improved verifying the availability to correct material distortion. • The scale cabin structures with Q345 steel were discussed to predict the prototype cabin structure model with 921 steels