Simulation of Mechanical System Kinematic Operation Subsequent to High Intensity Loading
Navy SBIR FY2014.1

Sol No.: Navy SBIR FY2014.1
Topic No.: N141-032
Topic Title: Simulation of Mechanical System Kinematic Operation Subsequent to High Intensity Loading
Proposal No.: N141-032-0318
Firm: Weidlinger Associates, Inc.
40 Wall Street
18th Floor
New York, New York 10005-1304
Contact: Jeffrey Cipolla
Phone: (202) 649-2466
Web Site:
Abstract: The simulation workflow to be developed in Phase I consists of an UNDEX simulation to establish the damage in the system, in terms of permanent set which may change the hatch actuation forces and simulation of the kinematics of the damaged elements to determine qualification. UNDEX simulations using finite element codes such as EPSA are in wide use throughout the NAVSEA community and their validation is taken as a given in this document. At issue is the transfer of the damaged state to a quasi-static simulation of SHKO, which includes the effects of friction and material damage. Using simulations in place of large-scale testing is feasible, based on these initial assessments. Future work will include prototyping such a workflow: shot selection, UNDEX analysis, mapping of the damaged post-UNDEX state, SHKO, and quantification of uncertainty of hatch operability. In addition, test planning for the supporting material and unit tests will be done.
Benefits: Submarine hatches are mechanically complex, SUBSAFE-critical items. For qualification, the hatch system must demonstrate operability after UNDEX events. In past SSBNs, the UNDEX qualification of submarine hatch kinematic operability (SHKO) has entailed full-scale testing of the missile tube structure. For the Ohio Replacement Program (ORP), such testing is estimated to cost $10-15M ; this corresponds to at least 30 work-year equivalents (WYE) for UNDEX analysis. The transition of these elements to Qualification by Analysis (QBA) would represent significant cost savings over full-scale testing.