Study on the dynamic ultimate strength of cracked thin plates under in-plane impact load

Crack is a common defect in ship operations and can significantly decrease the ultimate strength of hull structures. This research investigates the dynamic buckling and collapse behavior of cracked thin plates when subjected to longitudinal in-plane impact loads. The nonlinear finite element method is employed to carry out the analysis. The paper thoroughly examines the effects of various parameters, including crack length, crack angle, crack positions, plate length, aspect ratio, slenderness ratio, and strain rate. The numerical results are validated by comparing them with data from other papers. Furthermore, based on the outcomes of 572 groups of plates, an empirical formula is developed using a curve fitting method to predict the dynamic ultimate strength of cracked plates. This formula is expressed as a function of loading speed and geometric parameters, and its reliability and accuracy are verified. The findings of this research provide valuable guidance for assessing the safety of aging hull structures under in-plane impact loads.