Joint T&R Panel Session Current Needs in Structural Research – A View From the Hull Structure Committee Rick Ashcroft General Dynamics NASSCO Chair, Hull Structure Committee

SNAME Involvement SNAME is involved with research through its T&R program The Hull Structure Committee HS-1: Hull Loadings (Allen Engle) HS-2: Impact Loading and Response (Greg Hermanski) HS-3: Stress Analysis and Strength of Elements (vacant) HS-4: Design Procedure and Philosophy (Matt Collette) HS-7: Vibrations (Rich Sonnenschein) HS-9: Materials (Derek Novak) HS-12: Hull Instrumentation (Rick Ashcroft)

Current HSC Projects HS-1: Supporting the Task Group on Loads and creating Model Test Guidelines (expected release 2012) HS-9: T&R Bulletin 2-33 A Guide to Materials Engineering for the Maritime Industry (expected release 2011)

Ship Structure Committee SNAME HSC Supports the SSC Review proposals and recommend potential projects Since projects completed 2011: 19 proposals reviewed 10 aluminum (strength, fatigue, welding, alloys) Balance on load prediction, design guides, ice related Top 5 passed to SSC for further consideration Currently 10 projects in progress with SSC funding

Current SSC Projects

National Shipbuilding Research Program SNAME also supports NSRP, providing technical experts for project oversight via Committee and Panel membership Currently 5 major structures related NSRP Projects Analysis and verification, welding, ice reinforcement Also 4 smaller panel projects related to structures

Linear versus Non-Linear FEA Deformation and Stress Based on Simple Linear Analysis Deformation and Stress Based on Non-Linear Analysis

Current Focus of R&D Projects Aluminum, particularly fatigue and welding related Composites Load prediction, particularly ice and slamming

Future Research Topics Additional focus on high strength lightweight structure of all materials Prediction and control of welding distortion in thin steel and aluminum Improved techniques for estimating hydrodynamic and inertial loads including something between linear and RANS Better techniques of modeling HAZ and weld areas Better methods of assessing ultimate strength Validated non-linear finite element modeling techniques for typical ship structures Composites – better definition damage tolerance and development of non-destructive inspection techniques Real-time measurement of stress and fatigue accumulation including onset of cracks and tracking crack growth Full scale trials to better quantify both quasi steady state and impact ice loads