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Historical OverviewHistorical Overview
Dry mass trends of NASA science satellites
•1950’s-1990: mass increasing for scientific spacecraft
•90’s: mass decreasing
SMALLSAT SMALLSAT REVOLUTIONREVOLUTION
Smaller Lighter Cheaper Satellites
Technology OverviewTechnology Overview
•Materials and structures have been responsible for major improvements in aerospace systems•For future missions the development of new structures and materials can be a key element in reducing operating cost and gross weight
MultifunctionalStructures
Smart Structures
MFS-Description MFS-Description
•structural composite panel•Multi-ChipModules•Cu/Pi patches•heat-transferring devices embedded•outer surface acting as a radiator•flexible jumpers•electrical circuitry in the Cu/Pi layers•protective coverSynergistic integration of Electronics,
Structural and Thermal control technologies
MFS-BenefitsMFS-Benefits
Traditional Design MFS Design Subsystem Mass(Kg) Volume(in3) Mass(Kg) Volume(in3)
C&DH 10.0 681 0.6 16 Power Distr/Drive Unit 9.3 850
Pyro Initiator Unit 4.0 189 Charge Control Unit 1.2 189
0.6
16
Cabling (Misc.) 18.2 400 1.0 42 •Cable-free S/C with 70% reduction in electronic enclosures and harness•>25% increase in payload fraction•>50% increase in S/C volume available for instruments or propellant tankage•reduced cost as MFS offers modular architecture•reduced “touch labor” needed in the final S/C integration•enhanced robustness and reliability•wide applicability to several missions
Examples of future Examples of future usersusers:•Next Generation Space Telescope
•Space Based Infrared System
•National Polar Orbiting Operational
Environmental Satellite
•Mars missions
MFS-State of the artMFS-State of the art
Current efforts incorporating MFS elements:•New Millenium Program-Deep Space 1 mission•New Millenium Program-Deep Space 2 mission•Mighty Sat SAFI (AFRL)•STRV 1 (DERA/BMDO/JPL)•New Millenium Program-EO1
Technology maturity Description
Component validation Temp and vibe tests on SIES CR&D (AFRL)
System/Substystem or Prototype demonstration
NMP DS1 MFS experiment Development effort
System prototype demonstration NMP DS1 MFS experiment
Flight qualification Test data on DS1
Flight mission success NMP DS1, NMP DS2, STRV
DS 1-Deep Space 1 MissionDS 1-Deep Space 1 Mission
MFS exp
DS1 is managed by NASA\JPL
DS1 GOAL:Validate technologies required for new types of missions
•Oct ’98: launch•Sept ’99: primary mission ended•April ’99: 7 technologies had been successfully tested
MFS experiment had been 100% validatedMFS experiment had been 100% validated
DS 1-MFS ExperimentDS 1-MFS Experiment
Experiment GoalsDemonstrate and validate MFS technology:– Produceability– Flightworthiness– Flex circuit patches and jumpers on structure– Socketed MCM– Distributed temperature measurements – Flex circuit connections – Hybrid cover including composite radiation shielding material
Two validation experiments:•Continuity check: copper polyimide layers and flex jumpers are verified as maintaining integrity•Thermal gradient: cycling the HiLoPDM MCM switching element which powers a thermal simulator and analyzing the thermal gradient on the panel
DS 1-ResultsDS 1-Results
GROUND TESTING:•Random and sine-sweep vibration tests•Thermal vacuum tests
•Mechanical and electrical integrity well maintained•MCM-component temperatures within operational temperature regions
FLIGHT VALIDATION:
•Performance consistent with preflight tests•No degradation in flex conductor performance•No degradation of signal in the flight MCM socket system•No failures in the data collection / interfacing electronics•100% complete (03/99)
Technology effort Technology effort requestedrequestedInnovative technologies are sought in the following areas:
•Techniques for structural integration of low-volume electronics packaging (chip-on-structure, chip-on-flex, imbedded electronics)•Concepts for integrating electronics, thermal management, radiation shielding with lightweight composite structures•Methods to rapidly assemble and disassemble or repair highly integrated multifunctional structures or imbedded electronics•Multifunctional structures that incorporate both power generation and telecommunications functions•Interchangeable structural components that can be used for more than one function•Integration of two or more spacecraft systems functions in miniature components for micro-spacecraft and sensorcraft
ConclusionsConclusions
•Multifunctional Structures methods are valid for flight designs
Design, integration, test, rework, flight and operation all completed successfully
• MFS Technology is a very strong candidate for reducing mass and volume in spacecraft design
Savings from 50% to 80% in both areas
•MFS technology supports mass production of spacecraftCost-effective, modular, reliable and repairable architecture
MFS IS READY FOR USE AS THE PRIMARY LOAD-MFS IS READY FOR USE AS THE PRIMARY LOAD-BEARING AND ELECTRICAL CABLING METHOD BEARING AND ELECTRICAL CABLING METHOD FOR CABLE-FREE SPACECRAFTFOR CABLE-FREE SPACECRAFT
SMART-SMART-DescriptionDescription
A smart material provides a certain function (sensing, actuation) by converting ENERGY from one form to another.
PiezoceramicsPiezopolymersElectrostrictors
Electrorheol. fluids
MagnetostrictorsMagnetorheol. fluids
Shape memory alloysShape memory ceramicsShape memory polymers
Optical fibers
Ionic polymeric gels
SENSING
MECHANICAL FORCE, DISPLACEMENT
Electric variables (C,R,Q)Magnetic variables (R,L)
Resistance
Light intensity
Concentration (PH)
PiezoceramicsPiezopolymersElectrostrictors
Electrorheol. fluids
MagnetostrictorsMagnetorheol. fluids
Shape memory alloysShape memory ceramicsShape memory polymers
Special gels
Ionic polymeric gels
ACTUATION
Electric field
Magnetic field
Thermal energy
Light
Chemical energy
SMART-SMART-BenefitsBenefitsTRADITIONAL
TECHNOLOGIESStres
s (Mpa
)
Strain
Efficiency
Bandwidth (Hz)
Work (J/cm2)
Power (J/cm3)
Electromagnetic 0.02 0.5 90% 20 0.005 0.1
Hydraulical 20 0.5 80% 4 5 20
Pneumatic 0.7 0.5 90% 20 0.175 3.5
Muscle 0.35 0.2 30% 10 0.035 0.35NEW
TECHNOLOGIESStres
s (Mpa
)
Strain
Efficiency
Bandwidth (Hz)
Work (J/cm2)
Power (J/cm3)
Shape memory 200 0.1 3% 3 10 30
Electrostrictive 50 0.002
50% 5000 0.05 250
Piezoelectric 35 0.002
50% 5000 0.035 175
Magnetostrictive 35 0.002
80% 2000 0.035 70
Contractile polymer
0.3 0.5 30% 10 0.075 0.75
• Vibration control• Damage detection• Increasing passengers comfort• Improving precision pointing
•Improving aerodynamics•Reducing manufacturing and assembly costs•Increasing structural life
SMART-State of the artSMART-State of the art1880: Pierre and Jacques Curie discover piezoelectricity
1882-1917: piezoelectric research goes on as a mathematical challenge
1920-1965: first applications (vibration damping, microphones, transducers)
1965-1980: Japanese developments (signal filters, igniters, ultrasonic motors)
Late 60’s: first concept of synthesizing of smart materials and structures
•Early 90’s: work on vibration suppression applications in spacecraft, funded by the Ballistic Missile Defense Organization (BMDO) and the US Air Force
•Since the early 90’s the Army Research Office (ARO), the Air Force (AF), the Defense Advanced Research Project Agency (DARPA), the National Aeronautics and Space Administration (NASA) and the Navy have ongoing programs to demonstrate the application of smart structures in a variety of systems
At present there are three approaches to develop smart materials and structures:
1.Synthesize new materials at the atomic and molecular level
2.Develop systems with actuators and sensors attached to conventional structures
3.Develop new materials by synthesizing composite systems from known materials. These composites contain active constituents and are used to fabricate the structure
SMART-ResearchSMART-Research
Smart materials and structures interest different fields of research:
• active noise control
• active vibration control
• precision machining and micropositioning
• aeroelastic control
• biomechanical and biomedical (artificial muscles, valves)
• process control (on/off shape control of solar reflectors)
• active damage control (detection and control of delamination growth in composite beams)
• seismic mitigation
• corrections in optical systems
• discrete and distributed actuation and control
• ultrasonic motor
Generalized acoustic structure with local panel actuation
SMART-Commercial SMART-Commercial applicationsapplicationsSmart materials have also a wide variety of commercial applications:
• piezo-damped skis and snowboards
• smart-shock for mountain bikes
• piezoelectric actuators for pneumatic valves
• electronic water-skis
• smart baseball bats
• piezoelectric flat speaker technology for computer systems
• omnicom multifunction transducer(provides vibration, tone alert and hands-free loudspeaker functions in one component)
SMART-Ongoing programsSMART-Ongoing programs•SAMPSON: Smart aircraft and marine projects demonstration Shape control and acoustic control (DARPA, Penn State Univ, Boeing Company)
•SMART ROTOR Control of trailing edge flaps and twist control for helicopter rotor blades (MIT, UCLA, ARO, Boeing, DARPA)
• SMART WING Improve aerodynamic performance (lift/drag and maneuver performance) (Northrop, Lockheed Martin, Georgia Tech)
THE NUMEROUS SYSTEM DEMONSTRATIONS RECENTLY COMPLETED OR CURRENTLY UNDERWAY INDICATE THAT SMART TECHNOLOGIES WILL LIKELY PROVIDE NEW AND INNOVATIVE CAPABILITIES IN FUTURE COMMERCIAL AND MILITARY AEROSPACE SYSTEMS
SMART-New technologies 1SMART-New technologies 1
ACTIVE FIBER COMPOSITES
Active fibers introduced into soft polymers; electrode patterns direct field and polarization along fibers. ADVANTAGES: high strength, directional actuation, conformable/large area, high energy densitySINGLE-CRYSTAL PIEZOELECTRICS
Single-crystal piezoelectrics show high strength, large piezoelectric effects (very high electromechanical coupling factors), field-induced strains an order of magnitude greater than strains induced in conventional piezoceramics
TECHNICAL ISSUES
•Fabrication methods
•Reliable materials
•Lightweight materials
•Integrated system design
•Fatigue life characteristics
•Maintenance and repair procedures
SMART-SMART-New technologies 2New technologies 2
MEMS: Microelectromechanical systems
Electrical and mechanical functions on a single chip, realized using techniques utilized in the manufacture of microelectronic devices (micromachining)
APPLICATIONS:•Nozzles and nozzles arrays•Microfluidic systems•Sensors, actuators•Positioners•Pumps, valves
MAD: Meso-scale actuator
Combine MEMS technologies and smart materials to develop a meso-scale large force and large displacement actuator
SMARTSMART-Future 1-Future 1
GOOD PROGRESS IS BEING MADE IN THE DEVELOPMENT OF ELECTRONICS, CONTROL APPROACHES AND ANALYSIS TECHNIQUES. MORE WORK IS NEEDED TO DEVELOP FABRICATION TECHNIQUES TO MAKE SMART SYSTEMS AFFORDABLE. REALIZING MANY OF THE ENVISIONED APPLICATIONS WILL DEPEND UPON THE DEVELOPMENT OF HIGHER AUTHORITY, SOLID-STATE ACTUATORS AND INNOVATIVE CONCEPTS.
Piezo strips
MICRO AIRCRAFT(mass of less than 10 grams)
Project developed at MIT as a mechanical counterpart to biological winged flight; solid state flapping wing propulsion and control using piezoelectric bimorph actuators
Motivations:
•Applications in surveillance operations
•Challenging and exciting
SMART-Future 2SMART-Future 2
SMART-MFSSMART-MFS
New Shape Memory New Shape Memory MaterialsMaterials
Piezo pumpsPiezo pumps
Introduzione alle strutture Introduzione alle strutture intelligentiintelligenti
CSM27 Luglio 2000
Prof. Paolo Gaudenzi
1. Strutture tradizionali e strutture intelligenti
2. Stato dell’arte sulla tecnologia
3. Strutture multifunzionali