Uniform Blast Loading on Stiffened Rectangular Plates by Welding Line: Experimental Investigation and Modelling Using GMDH Neural Network

In the present study, the dynamic response of rectangular steel plates under repeated impulsive loading was investigated. In this regard, experiments were performed on three different structures: unstiffened, stiffened with one and two welding lines. To investigate the deformation modes and the failure mechanism of the experimental specimens, dynamic loads in a wide range were applied up to 3 loads by 25, 35, 45, and 50 g charge masses. Experimental observations demonstrate that with increasing charge mass, the Mode Ia and Mode Ib are observed in a higher charge mass and loading repetitions in a higher number. For the unstiffened plate, at the 3rd load with a mass of 25g, a change Mode Ia is observed, however, the same deformation mode occurs for the stiffened plate with a single and two weld lines at the 3rd blast load by 35g and 45 g charge mass, respectively. These observations indicate the effect of the weld line and its numbers on the variation of failure modes. Furthermore, in the numerical modeling section, the Group Method of Data Handling (GMDH) neural network was used to present a mathematical model based on dimensionless numbers to predict the maximum permanent deflection of tested specimens. Good agreement between the proposed model and the corresponding experimental results is obtained and all data points are within the ±10% error range for every two patterns.