New Technique Reduce Steel Warping in Ship Building

A new process has been developed to enable shipbuilders to save production costs and improve build time while reducing distortion of lightweight materials.
The Joining-3 Project, led by Huntington Ingalls Industries’ Ingalls Shipbuilding division, developed computer models to better predict where distortion and warping will occur when steel plates are welded together, ultimately reconfiguring the welding sequence. Tests involving a U.S. Coast Guard Cutter demonstrated a 30 percent reduction in distortion and a 13 percent reduction in production costs compared to similar, previous cutter production units.

The project was run via LIFT – Lightweight Innovations For Tomorrow, a Manufacturing USA institute. Project partners included government: NSWC-Carderock Division, NAVSEA, industry: American Bureau of Shipping (ABS), Comau, and ESI and research: the University of Michigan, EWI, Massachusetts Institute of Technology and The Ohio State University.

“As naval ship designs have trended toward using thinner and higher strength materials to reduce structural weight and add new combat capability, controlling the quality and cost of distortion has increasingly and adversely affected the shipbuilding industry,” said T.D. Huang, Principal Engineer, Huntington Ingalls Industries. “The LIFT project has provided an avenue to collaborate with world-class experts and systematically address thin steel distortion.”

Over two years, the Joining-3 Project team fabricating 19 test panels featuring different variables and assembly sequences and employed Integrated Computational Materials Engineering (ICME) modeling to establish recommended fitting, welding and assembly sequences for optimized distortion control. Recommended procedures were then employed on a full-scale mock-up unit.

The modeling and streamlined process is currently being implemented by Ingalls to predict changes in design and the associated costs across all production platforms. A follow-on project to evaluate advanced steel alloys for ICME implementation has been approved by LIFT for kick-off this summer.