The objective of this project was to evaluate cast tee sections as a potential replacement for welded joints. A joint design for the DDG 1000 peripheral vertical launch system (PVLS) consists of HSLA-100 steel plates that are fabricated by welding lengthwise. Distortion, quality/rework, and production costs of lengthwise-welded sections are of concern along with fracturing that occurred during explosion testing. NMC worked with NSWCCD, NGSB-NN and BIW to characterize a cast HY-100 steel component.
The design of the Tee-sections for the DDG peripheral vertical launch system (PVLS) consists of HSLA-100 steel plates fabricated by lengthwise welds. Distortion, quality/rework, and production costs of lengthwise-welded sections are of concern. This propject examined an alternative production technique for these sections, both for risk reduction and for a potential reduction in production costs.
The static and dynamic material properties must be characterized for input into models that are used to predict blast performance. Because these are new and critical components, the cast part design must be optimized for producibility, tolerances and possibly weight reduction. NMC will develop static and dynamic material property data for input to the blast performance models. Specimens will be obtained from existing in-house HY-100 casting material, and verified on material from a demonstration cast Tee section to be procured by NGSS.
A one-piece alternative to welded Tee sections could potentially improve the reliability of the PVLS structure in explosive conditions and possibly reduce procurement and weld fabrication costs.
The findings of this project were not implemented due to procurement cost and schedule.