Survivable Structures Survivable Ship Structures Ship / Vehicle Protection Systems

Transcription

1 Survivable Structures Survivable Ship Structures Ship / Vehicle Protection Systems Presented to Committee on Naval Engineering in the 21st Century Roshdy George S. Barsoum Office of Naval Research Ship Systems and Engineering Div. Code 331 Distribution Statement A: Distribution Unlimited

2 Survivable Structures OBJECTIVE: Hybrid Composite and Metallic Hulls Survivability, Affordability, Stealth, Strength, Durability and light weight for combatants and high speed ships. Lighter/ cheaper platform and personnel protection system/armor, which defeats several threats Polymer Coatings. S&T products Strength of Composite Hull following battle Damage Hybrid Joint Structural Response Design & Structural Response of Composite and Advanced Hull Forms Energy Absorbing structures Failure models/ simulation of UNDEX, AirEx, ballistics Optimization methods for lighter/ cheaper EFP armor and protection systems for ships/ submarines. Design/Simulation capability for crew protection against shock and Traumatic Brain Injury TBI. Design capability of lighter Multi Functional Polymers for Survivability (protection/stealth). TECHNICAL CHALLENGES - Steel-to-Composite Joints critical part-solution at hand. - Scaling of test results and properties of adhesives under shock Simulation: Multi-scale Methods in Ship UNDEX Whipping Testing/ Verification: sea Loads and fatigue of a hybrid Hull - In-situ measurements at extreme loading and rates - Mechanisms in high strain rate under UNDEX, Blast and Ballistics - Mechanisms in Polymers: strain rate sensitivity, suppression of shear localization, phase transformation (rubbery-glass transition) - Extremely high rates ( > 10E6 /Sec) - Molecular dynamics simulation of elastomers at extreme rates - Engineering of polymers-by-design. APPROACH Test scaled models of hybrid hull concepts New and conventional metallic to composite joints to achieve ductile failure under dynamic loading Understand sea loads and fatigue and UNDEX Whipping behavior of Hybrid Hull Perform tests at the threat level and use high speed photographyflash x-ray. SAXS and WAXS- Perform simulation to understand behavior. Experiments at max possible rates and use Time -Temperature superposition (relaxation theory) and high frequency - dielectric loss at high pressure (molecular dynamic theory) compression shear plate impact at very higher rates. Constitutive models and test models in simple ballistic and reversed ballistic experiments.

3 Energy Saving through Lightweight Structures Low Cost Highly Efficient Hull Shape Hybrid Ship Hull Low Cost Composites for Complex hydrodynamic shapes, result in reduced drag/resistance and improved performance and fuel efficiency Complex shapes for bow and stern can reduce Hydro Acoustic signature Signature: Non-Magnetic Materials Steel Hull / Composite Bow & Stern Frame structure for Control of Acoustic Sig. Low-Cost Fabrication of Complex Shaped Structure Lower Hull Whipping Stresses Shipyard Block outfitting DD-21 Hydrodynamic Model R.G. Barsoum, 331 Low cost Composite for Complex shapes for Stern, Hull and Bow result in large energy saving

4 Survivable Ship Structures Hogging and sagging of hybrid hull Sea Loads Hogging and Sagging: Loaded 40% above ABS design load Survivability after battle damage Blow out Panels to relieve Internal Explosion Loaded up to design load no further yielding 9 Blow out panels Fatigue- Large scale testing of Hybrid Hull 32500,000 cycles at 1.3 x design load Additional 317,000 cycles, cracks started to appear in composite panel. Repair welds and drill holes to stop crack propagation 1.75 x design load: yield in steel and cracking in the adhesive at the steel to composite frame joints Exceed all ABS and Navy requirements. 6.5 Ft Grenestedt/Lehigh

5 UNDEX Whipping comparison of Conventional Steel Hull and Hybrid Hull Same displacement and M ult Double the factor of safety of Conventional Hull z Composite panel Point mass y Cohesive elements z x Fluid (sea water) Hybrid Hull Whipping Draft W x d DDG type Conventional Steel Hull Bubble Pulsation Lua, U Maine

6 US-Japan Cooperative Research Advanced Hull Materials & Structures Technology Hybrid Hull UNDEX Aberdeen Test pond NSWCCD Full Scale Buckling Hybrid Joint SUS Joints Japan-CFRP Both failed in CFRP No failure at Joint UNDEX Hybrid Joint CFRP High Pressure Tank Test Plate US -GRP Both Failed in GRP section Rupture Disk Test Fixture Dynamic Pressure Loading UNDEX/TRDI/Japan Kamioka test pond

7 Composite-to Metallic Joint Mechanics Friction, De-cohesion Models, Fracture, Multi scale & Scaling Laws Rice (Harvard)- Dynamic Friction Coulomb Law is ill-posed, no unique answer Clifton (Brown)-New Dynamic friction Law- rate dependence To instron in train V. Gupta/UCLA E-glass beam Stainless Steel v ~ 2620 m/s ~ +2.1c H s ~ +1.3c H l Rosakis (Caltech) Test dynamic friction at composite to steel interface 20 mm Friction SS to composite Adhesive TWI/UK Sculpted steel surface Fish, RPI Multi scale Strength 100 BROWN U-Dynamic cohesion/ decohesion and friction laws at Composite/ steel interfaces size Scaling Laws Bazant/Northwestern

8 Slamming load facility-lehigh U. Speeds up to 50 Knots Hydro-elastic effects Composite panels

9 Energy saving through Lightweight Ship Protection System and Armor Explosion Resistant Coating (ERC) Lightweight Ship protection Blast Loading /UNDEX USMC Cougar Route vehicles Explosion Resistant Coating (ERC) Light armor against IEDs Uncoated Coated R.G. Barsoum, 331

10 Elastomer-Retardation of Necking and shear localization in Steel subject to blast loading Hutchinson/Harvard

11 Shear Localization suppression by Elastomers Belytchko (NorthWestern) Meshfree Methods for Polyurea XFEM to Model Cracking in Shells Enhanced elements for shear band modeling (UNDEX-AirEx) Tests by Mock NSWCDD Shot 725 ERC Elastomer Absorbs >50% of Energy Fish (RPI) Multi scale simulation modules compatible with commercial finite element code architecture (3-D effects, material studies) Ortiz (Caltech) 3-D simulation- cohesive elements for steel and phenomenological constitutive model (Penetration mechanics) Quadratic cohesive cohesive Law Element

12 SAXS P1000 P650 P250/1000 Edge Center of Impact Roland/NRL, Mock/NSWCDD, Balizer/NSWCCD

13 Failure Theory for Elastomer at high rate loading Michael Ortiz (PI), Caltech (in collaboration with Prof. K. Weinberg, Universität Siegen, Germany): Implemented, validated, calibrated time/temperature shift model Implemented, validated, calibrated Prony series into PU material model Implemented pressure-shear void growth model of ductile rupture Conducted validation runs of NSWC (Dahlgren) rod-impact experiments Simulations of Taylor-anvil rod-impact test of PU (shot 856, Courtesy W. Mock,NSWC)

14 Extremely High Strain rates and pressure at very high impact velocity Polymer Constitutive Models are extrapolated from Hopkinson B, Pressure Shear Plate Impact and Time-Temperature relaxation Curve Computational Methods Lagrangian (ABAQUS/Autodyn/DYNA) Arbitrary Lagrange-Euler (ALE)(DYSMAS) Smooth particle Hydrodynamics (SPH)-CTH Effective Stress (GPa) GPa, s GPa, s GPa, s GPa, s -1 barp4: Unconfined SPHB (UCSD) puc11c: Confined SPHB (UCSD) 404: PSPI (Brown) 501: PSPI (Brown) 502: PSPI (Brown) 0.013GPa, s GPa, s GPa, s Effective Strain Ave. Pressure Range in Polymer Mpa ( ksi) Strain Rate > 10E6/sec Tech.Challenge: In-Situ Measurement

15 Objectives: Basic Research Challenge: Elastomeric polymer by-design for protection warfighter against Traumatic Brain Injury (TBI) by diverting and dissipating blast induced shock waves form the head. Approach Building on successful test results on Explosion Resistant Coating for ship and vehicle protection, ONR is leading a Basic Research Challenge to develop polymers-by-design to divert and dissipate shockwaves from the head and thus prevent Traumatic Brain Injury - TBI. Tests and theoretical developments on polymers, indicate that these polymers can provide the necessary protection against TBI. Recent investigations into blast resistant properties of polyureas and other multi-phase polymeric elastomers indicate that they can dissipate broad bands of frequencies such as those in blast events. Polyurea polymers have been shown to absorb shock in quite a different manner than any ballistic material known to the armor community. POLYMER BY-DESIGN FOR PROTECTION AGAINST TRAUMATIC BRAIN INJURY Molecularscale 3WC NN T Polymer Synthesis έ optimization Continuum Simulation LFT - NSWCCD UCSD, Penn State, MIT SEPT 2009 Provide lightweight polymers, which divert and dissipate the shockwave from the head, in addition to improving the ballistic, blast and impact performance of the helmet material and thus prevent Traumatic Brain Injury TBI. Current conflicts have seen a dramatic increase in Traumatic Brain Injury (TBI), due to improvement in body armor and higher soldier survivability from fragments and other lethal injuries. Tests and theoretical developments on polymers (Explosion Resistant Coating), indicate that these polymers can provide the necessary protection against TBI. Collaboration with Codes 30, 332, 34 ARO and JIEDDO.