Fire Simulation and Residual Strength Prediction Tool for Aluminum Ship Structures During and After Fire Navy SBIR FY2010.2 Sol No.: Navy SBIR FY2010.2 Topic No.: N102-173 Topic Title: Fire Simulation and Residual Strength Prediction Tool for Aluminum Ship Structures During and After Fire Proposal No.: N102-173-0919 Firm: Global Engineering and Materials, Inc. 11 Alscot Drive East Lyme, Connecticut 06333 Contact: Jim Lua Phone: (860) 367-4970 Web Site: www.GEM-Consultant.com Abstract: A 3D non-linear and rate-dependent constitutive model will be developed and implemented within GEM's Abaqus Fire Interface Simulator Toolkit (AFIST) to characterize the time-, stress-, and temperature-dependent material response of aluminum alloys. Both the material and geometric non-linearities will be characterized based on Abaqus' kinematic description, coupled with its user-defined subroutines. The large deformation model will be formulated based on the additive decomposition of the strain rate tensor in elastic, thermal, and viscoplastic parts. To capture the loading and unloading path in an aluminum ship structural component during a fire, a flow rule will be formulated based on a function of the equivalent stress and the deviatoric stress tensor of the temperature field and of a set of internal state variables. Both the steady state and creep test data at coupon level will be collected to quantify the model parameters and the validity of the developed non-linear rate-dependent constitutive model will be examined via its simulation of the transient state tests. A hybrid implicit and explicit integration scheme will be implemented in AFIST to further enhance the solution efficiency and numerical stability. GEM has secured model validation support from VT and application guidance from NGSB and NSWCCD. Benefits: The results from this research will have significant benefits and commercial application in the aerospace, DoD labs, and shipping industries. It will result in: 1) an accurate material response model under an arbitrary combination of time, stress, and temperature; 2) a commercially viable, accurate, computationally efficient, and user-friendly residual structural integrity assessment tool for fire damage assessment of aluminum structures; 3) a virtual testing tool to reduce current certification and qualification costs which are heavily driven by sub-element and full-scale component testing for validation of structural integrity and durability when subjected to fire exposure; and 4) innovative design and fabrication procedures to minimize the risk of fire damage of aluminum ship structures. The tool can be used by USN and ship industries as follows: 1) to accelerate thermal damage assessment, determine effective insulation requirements, assist in decision making for effective repairs, and design reliable fire protection systems permitting maximum escape time; 2) for ship certification and design agencies to specify fire performance limits and safety standards; 3) for ship manufacturers to provide optimal designs via the effective use of new materials, fabrication procedures, and fire protection systems; and 4) by commercial and military industries to reduce the cost of test-driven design and process iterations with the use of the virtual testing tool. Return