Methods for predicting the ultimate/buckling strength of ship structures have been extensively improved in terms of design formulas and analytical solutions. In recent years, the design strategy of ships and offshore structures has tended to emphasize lighter builds and improve operational safety. Therefore, the corresponding geometrical changes in design necessitate the use of high-tensile steel and thin plates. However, the existing design formulas were mainly developed for thick plates and mild steels. Therefore, the calculation methods require appropriate modification for new designs beased on high-tensile steel and thin plates. In this study, a modified formula was developed to predict the ultimate strength of thin steel plates subjected to compressive and shear loads. Based on the numerical results, the effects of the yield stress, slenderness ratio, and loading condition on the buckling/ultimate strength of steel plates were examined, and a newly modified double-beta parameter formula was developed. The results were used to derive and modify existing closed-form expressions and empirical formulas to predict the ultimate strength of thin-walled steel structures.

Abstract
1. Introduction
2. FE model and calculation method
    2.1 Initial imperfections
    2.2 Material properties
    2.3 Parametric Study
3. FEA Results
4. Development of modified formulation
5. Conclusion and remarks
References

• Joo Shin Park(Ship and Offshore Research Institute, Samsung Heavy Industry Co. Ltd.)
• Jung Kwan Seo(The Korea Ship and Offshore Research Institute/Department of Naval Architecture & Ocean Engineering, Pusan National University) Corresponding Author