BPNN-Assisted restoration of buckling resistance of dented torispherical heads using CFRP

Abstract

To mitigate the adverse effect of a dent on the load-bearing capacity of torispherical heads, this study proposes a method for repairing dented torispherical heads with carbon-fibre-reinforced polymer (CFRP). The buckling behaviours of four dented torispherical heads, two of which were repaired using the proposed method, were studied through hydrostatic experiments and finite-element analysis (FEA). Experimental buckling load values were consistent with the FEA-based numerical predictions. Subsequently, the effects of the CFRP repair area and fibre orientation on the repair efficacy were investigated through FEA. Furthermore, a backpropagation neural network (BPNN) model was trained to predict the buckling load of repaired torispherical heads. The trained BPNN model was used to analyse the interactive effects of dent depth, dent position, and number of CFRP layers on the buckling load of a repaired torispherical head. The buckling load of dented torispherical heads decreased to 73.15 % of the undented state. After repairing with CFRP, the buckling load was restored to 101.01 % of the undented state. Meanwhile, the trained BPNN model with R² of 0.9895 on the test set was found to have high prediction accuracy on the buckling load of repaired torispherical heads. Results indicated that a dent can considerably reduce the buckling load of torispherical heads. However, the load-bearing capacity of dented torispherical heads can be fully restored by using the proposed repair method. The findings of this research can act as a reference for the development of buckling resistance restoration methods for dented pressure hulls.