Dynamic Analysis Of Defective Stiffened Plate Structural Under Impact Loading By Finite-element

With the unceasing development of modern industrial technology, engineering structure also more and more developes to thin and light-duty direction, at the meanwhile high strength and composite material is used in engineering, stiffened plate structure got a wide application. Stiffened plates have wide applications in aerospace, bridge, ship and some other engineering activities due to their economic and stctural benefits.Stiffening a plate can achieve higher strength and weight ratio of the structure compared to a bare plate having same material.Although the use of stiffened plate structure can bring a lot of advantage, but due to the introduction of reinforcement will make structure produce discontinuity and inhomogeneity,while most of the engineering structure were used under dynamic loading, these impact process is complicated nonlinear dynamic response, the role impact load has big intensity, short time, the structure under impact load will occur dynamic failure, leading to an overall bearing capacity down even completely exhausted. In addition, board inside inevitably exists some uncertain initial defects, such as crack, holes or initial deflection etc, nonlinear dynamic response of structure is very sensitive to these initial defects, so in order to guarantee the safety of stiffened plate structure,it must consider the most unfavorable initial defects effects. Further study of stiffened plate structure's dynamic response and the impact of the dynamic buckling problem with initial defects is very necessary.A lot of simulation analysis shows:if properly simulating boundary condition, ways of bearing load of structure, nonlinear properties of materials, adopting rational unit types and grid scale, and comprehensivly considerating the various factors of impact dynamics analysis, simulation can obtain more accurate results. This paper studys the impact dynamics of stiffened plate structure by using finite element analysis software ANSYS/LS-DYNA.first, based on discrete stiffened plate model, considered the large deformation and ignored damping, investigated the influence of stiffened plate dynamic response by different impact load form, and discussed the influence of different impact velocity, reinforced number and different forms to an initial defects of stiffened plate dynamic response.Then consider defects of stiffened plate structure, from the macroscopic point of view, to simulate the structure strength and crack propagation of central through crack defect plate and stiffened plate under impact loading by finite element method. Discussing the establishment of geometric models, the selection of materials and methods, and then after a lot of finite element analysis of the results of various parameters, such as impact velocity, reinforced number and forms of crack plate and shell strength, and in the light of the influence of crack propagation behavior, tentativly summarizes some laws of stiffened plate dynamic response.