| Composites are widely used in aerospace structures due to their high specific modulus,high specific strength,high design ability and corrosion resistance.Generally,the composite stiffened plate structure is composed of skin,ribs and transverse frame,and its bearing capacity and stability are affected by many factors,such as type of ribs,bonding process,manufacturing damage,impact damage and so on.Therefore,the systematic analysis of the influence of various factors on the bearing capacity of the stiffened plates,and the effective evaluation and rapid prediction of the bearing capacity and stability of the composite stiffened panels are of positive significance for the designers to carry out structural analysis and optimization.In this study,the engineering analysis method and the finite element analysis method for predicting the bearing performance of T-type and I-type stiffened panels were studied respectively,and the experimental verification was carried out.First,engineering analysis method is often used in the initial design stage of stiffened panels because of its fast calculation speed,but it's calculation precision is not enough.In view of the current engineering analysis method,in this study,the effective width formula is fitted by semi empirical and semi theoretical method to calculate the buckling load of T-type and Itype stiffened panels.The effectiveness of the formula is verified by finite element simulation and experiment.The calculated buckling loads of the stiffened panels with different density or different stiffened panels meet the engineering calculation accuracy,and the calculated results are relatively safe compared with the experimental results.Secondly,the finite element method is relatively reliable to analyze the influence of some parameters of the stiffened panel in the post-buckling calculation.In this study,the influences of the types of ribs,grids,the introduction of different modes,manufacturing damage and impact damage on the calculation of post buckling load of stiffened panels are analyzed.The finite element calculation results show that the estimation error of the compressive and shear ultimate load of the T-type and the I-type stiffened panel is-1.6% ? 12.8%?-3.1% ? 5.6%?-2.4% ? 16.5% and-5.8 ? 9.3%,respectively,which can meet the requirements of engineering precision after eliminating the discretization error.The results of finite element damage distribution are verified by experimental analysis.Finally,in order to quickly predict the buckling load of T-type and I-type stiffened panels,an engineering calculation software based on Matlab language was specially compiled.It is composed of equivalent compression stiffness,equivalent shear stiffness,compression buckling load,compression ultimate load and shear buckling load,etc.It not only avoids many and complicated formulas of engineering calculation,but also greatly improves calculation efficiency. |
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