SBIR-STTR Award

In this Phase I proposal DDL OMNI Engineering proposes to demonstrate the feasibility of an innovative composite Roll-On/Roll-Off (RO/RO) ramp concept that enables in-stream transfer of cargo from logistic supply ships to floating causeway RO/RO discharge facility (RRDF) platforms during sea state 5 (SS5) seaway conditions. The concept is based on the development of modular composite RO/RO ship ramp structures that incorporate several unique design features enabling the structure to respond in an acceptable manner to dynamic seaway conditions. These design features are: (1) a lightweight, high-strength and modular composite structure based upon application of low cost "Cell Core" technology; (2) smart composite manufacturing processes to permit low cost and reliable manufacture of the composite structural elements; and (3) the integration of flexible structural joints with elastomeric bearings and/or flexures (leaf springs) into the ramp support structure to provide supplemental motion compensation and controlled flexibility. Work will include both static and dynamic analyses of the proposed concept to estimate the relative motions between ramp ends and accelerations imparted to vehicles traversing the ramp structure. The concept will be refined during Phase I by using design optimization procedures to conduct performance and cost trade-offs. Benefits The proposed concept offers a potential to manufacture affordable composite ramps with a 40-60 % weight reduction compared to conventional steel ramps. The modular fabrication approach provides tremendous flexibility during design and manufacture of composite ramp structures of various dimensions, weight requirements, and rated load capacities. The modular approach enables application across all logistic supply ship classes. Private-sector applications include commercial shipping, high-speed ferries, and automobile carriers. Keywords Composites, Structures, Modular, Ramp, Cell Core, Manufacturing, Optimization, Lightweight

In this Phase II proposal DDL OMNI Engineering proposes to demonstrate the feasibility of an innovative composite Roll-On/Roll-Off (RO/RO) ship ramp concept that enables in-stream transfer of cargo from logistic supply ships to RO/RO discharge facility (RRDF) platforms during sea state 5 conditions. The concept is based on the development of composite RO/RO ship ramp structures that incorporate unique design features enabling the structure to respond in an acceptable manner to dynamic conditions. These design features are: (1) a lightweight, high-strength and modular composite structure based upon application of "Cell Core" technology; (2) smart manufacturing processes to permit low-cost and reliable manufacture of composite structures; (3) integrated flexible structural joints using elastomeric bushings; and (4) an integrated semi-active motion mitigation system using magnetorheological fluid dampers. Work will include finite element analysis, demonstration of “Smart” manufacturing processes, design optimization, and testing of full-scale and scaled specimens. The concept offers a potential to manufacture affordable composite ramps with a 40-60 % weight reduction compared to conventional steel ramps. The modular fabrication approach provides tremendous flexibility during design and manufacture of composite ramp structures of various dimensions, weight requirements, and rated load capacities. Private-sector applications include commercial shipping, high-speed ferries, and automobile carriers.

Keywords:
Composites, Structures, Lightweight, Modular, Ramp, Cell Core, Manufacturing, Optimization