Numerical Research On Dynamic Buckling Of The Imperfect Stiffened Plate Under Impacted Load

The stiffened plate effectively ensure the reliability and durability of the structure, and it can significantly reduce the structural weight to save structural materials. Due to its high efficiency and economical efficiency, the stiffened plate has been widely applied in the engineering field of shipbuilding, aerospace, bridges, buildings, etc. On the other hand, the stiffener’s introduction will bring the discontinuity and inhomogeneity of the structure, coupled with some uncertain initial structural defects(such as the initial deflection, depression, holes, crack, etc) which can be produced in the process of construction and lifecycle. So all of these imperfection make the behavior analysis of stiffened plates very complex.At present, buckling analysis of the ship structure are generally based on the assumption of a static load. However, in reality, the majority of the load of the ship’s structure are dynamic. As we know, static buckling only depends on the magnitude of the force, while the dynamic buckling depends not only on the magnitude of the force, but also with the duration, the change of the frequency of the force and the structural factors such as the initial defects. Because of the introduction of the time parameter makes the problem more complicated, and the related literature is also relatively rare. So further study of stiffened plate structure’s dynamic response and the impact of the dynamic buckling problem with initial defects is very necessary.In accordance with B-R(Budiansky-Roth) standards, this paper uses the nonlinear dynamic analysis software ANSYS/LS-DYNA to study dynamic buckling characteristics of the imperfect stiffened plate which contains initial defects(initial deflection, partial holes, cracks). For this purpose, the influence of initial geometric deflection, dynamic load duration, impact load form, stiffener size and angle of inclination are discussed.This paper introduces the direction of the structural dynamic stability. And then research actuality of dynamic buckling has been concluded from two aspects-periodic load and impact load. The paper also discussed the classification of the structural buckling problem and the characteristics of the dynamic buckling. And next the criterion of the dynamic buckling has been evaluated.The results of the paper show that all of these are important factors to affect the stiffened plate dynamic characteristics, but the degree of influence are not the same. The load carrying capacity of imperfect stiffened plate will be enhanced if the initial geometric deflection and the partial pore radius are decreased, and it is also important to select the appropriate stiffened plate’s size and form to improve the carrying capacity of the imperfect stiffened plate.