Analysis and Testing of Inelastic Buckling of a Ring Stiffened Cylinder

Abstract

Abstract Naval vessels fabricated from high strength steels (HY-100) traditionally require higher yield strength weld metal to protect the weld from high strains. However, these high strength welds are costly due to strict fabrication requirements. Alternatively, reduced fabrication costs can be achieved by using slightly lower strength welds designed for use with lower strength HY-80 steel. To verify the validity of this approach, the U.S. Navy is supporting the optimized weldment properties project to evaluate the effect of lower strength welds on the performance of welded structures and institute applicable design changes. One phase of this program included numerical and experimental evaluation of ring-stiffened cylinder structures under hydrostatic pressure loading. The objective was to modify the existing design criteria to account for the use of undermatched welds. Finite element analyses were developed using the ABAQUS and STAGS analysis codes. These analyses modeled the nonlinear, inelastic response of the structure and were used to predict buckling pressures for the structures. Experimental models were fabricated and tested to validate the numerical analyses. The experiments and analyses have resulted in design criteria modifications associated with the use of undermatched welds in hydrostatically loaded, ring-stiffened cylinder structures.