Stability And Ultimate Strength Analysis For Stiffened Plates With Cutout

In the hull structure, stiffened plate with openings is inescapability, the stress concentration problem has long been concerned by the majority of scholars and classification societies. In addition, with the depth study on ship safety and economy, and the concept of "ultimate strength " had been introduced in Common Structural Rules, it is necessity for the further study of structural stability and ultimate strength. The strength and stability analysis for stiffened plates with cutout under uniaxial load can provide a reference for engineer practice and is very significant.This paper adopt the finite element calculation method, carried out series of finite element calculation to analysis the strength stress concentration, stability and ultimate strength for stiffened plates with cutout under uniaxial load. Base on the finite element numerical calculation results, presented a formula for forecasting the ultimate strength of stiffened plates with cutout under uniaxial compression and discussed the simulation of residual stress in the finite element analysis of stiffened plates.In this thesis, the main works are as following:(1) Calculated the stress distribution of stiffened plates with cutout under uniaxial tension by finite element method, comparative analysis the stress concentration of stiffened plates with cutout between circular and oval, and discussed it’s strength after enhance.(2) Discussed the problem of finite element calculation method for stiffened plates with cutout, including the range of model selection, meshing and boundary conditions, and summarized a reasonable plan for eigenvalue buckling analysis and nonlinear finite element analysis. Carried out series of finite element calculation to analysis buckling eigenvalue of stiffened plates with cutout and discussed the influence of cutout between circular and oval on the buckling characteristics of stiffened plates.(3) Carried out series of nonlinear finite element calculation to analysis ultimate bearing capacity of stiffened plates with cutout under uniaxial compression, and discussed it’s influence between circular and oval. Base on the nonlinear finite element numerical calculation results, presented a formula for forecasting the ultimate strength of stiffened plates with cutout and carry out error analysis.(4) Discussed the nonlinear finite element method modeling technique for stiffened plate structures with residual stresses under uniaxial compression, include meshing in plate, the influence of transverse residual stress, the range of residual stress in angle bar and flat bar. Some important insights and conclusions are developed from the present study in order to provide a reference for the further study.