Analysis of a stiffener intersection eccentricity in a steel containment

A 1 : 8-scale steel containment model was fabricated, analyzed, and pressurized to failure by Sandia National Laboratories. Details of the containment construction are given and the analysis and testing are described in detail. During testing, the containment model ruptured. The failure is believed to have initiated near Equipment Hatch 1 and was attributed to a 1/2 in. eccentricity in a stiffener intersection detail. Post-test analysis of this detail was performed by Sandia using the MARC general purpose finite element analysis program. This analysis indicates a significant strain concentration in the 1/2 in. eccentricity. In the current work, a portion of the as-built 1 : 8-scale model surrounding Equipment Hatch 1 was analyzed using the ANSYS general purpose finite element program to verify the Sandia post-test analysis and to qualify the ANSYS program. Additionally, reduced size models of the failure region and of the corresponding region of a model with altered geometry were analyzed. The use of the ANSYS program was based on accessibility and cost considerations. This program has many of the features required for this analysis such as plasticity and large displacements