Smart Structures Overview Examples, 9/12/07 Prof. Doug Cairns
Structural Safety System Airworthiness authorities Regulatory Actions Fleet Surveillance Structural safety Design Fabrication Customer Support Maintenance Inspection Repair Reporting Airline operators Airplane manufacturer
Aloha Airlines Anomalous usage outside of the design envelope precipitated premature failure Many Ground Air Ground cycles, low airframe time, corrosive environment
IUTAM (cont.) Smart Structures encompasses many disciplines
Commercial Products Optechnology's Cementitious Composites Division About the Division Our cementitious composites division specializes in the design, development, and production of strategically tuned, absolutely resilient structures (STARS). These remarkable creations are composite structures that are fabricated by placing a low modulus, lightweight concrete over multiple layers of a relatively stiff reinforcement. Although STARS can be used for standard construction, they are specifically designed so that they can be highly stressed and deformed to store large amounts of elastic strain energy. When the structural response is modified as the service loads are decreased, the energy is released in a controlled fashion to do useful work.STARS are designed based on the strength, stiffness, and the position of the component materials in the composite section. Their ability to store and release energy depends upon a complex interaction between the shape, modal response, and the forcing function initiated to the structure. Our most advanced systems function as smart structures that include sensing elements to monitor structural integrity and control elements to adjust the dynamic response.
Smart Bandaids? CONTACT: Jonathan Sherwood (716) 273-4726 November 1, 2001 'Smart Bandage' Diagnoses Danger Before Infection Takes Hold Imagine placing an adhesive bandage on a cut and having the bandage tell you immediately that dangerous bacteria have gotten into the wound and that you need to seek a doctor's help. Researchers at the University of Rochester have taken the first major step toward a bandage that will change color depending on what kind of bacteria may be present in a wound. It can give an instant diagnosis as to whether the wound may require special care or what kind of antibiotics may work best in treating it. The bandage is part of the Center for Future Health's "smart medical home"-a series of devices working in conjunction in the home to monitor a family's health.
Joint US/Japan Program for Smart Buildings – Japanese Perspective INTRODUCTION A conventional structural system is designed to achieve a set of intended functions under pre-selected loads and forces. Such a conventional system can not successfully develop its ability against unexpected loads and forces unless a large safety factor is provided for safety limit states to take into account various uncertainties in load and force amplitudes and structural response. Furthermore, since seismic design requirements have been improved after each bitter lessons learned through past earthquake disasters, the safety level of old buildings is always inferior to new buildings as evidenced in many past earthquake disasters, e.g., the 1995 Kobe earthquake disaster. Strengthening or removal of those old buildings becomes necessary to protect societal welfare. Smart Structural Systems are defined as structural systems with a certain-level of autonomy relying on the embedded functions of sensors, actuators and processors, that can automatically adjust structural characteristics, in response to the change in external disturbance and environments, toward structural safety and serviceability as well as the elongation of structural service life.
Joint US/Japan Program for Smart Buildings – Japanese Perspective, cont. TARGET ISSUES The research and development are conducted focusing on the following issues. Concept and performance evaluation: A series of auto-adaptive and high-performance systems are developed, and methods of performance evaluation are investigated. Sensing of structure performance: Damage detection methods utilizing smart materials as sensors, such as Optical Fiber, Carbon Fiber, Shape Memory Alloy (SMA), and a Piezoelectric Ceramic (PZT) in addition to existing sensors are investigated, and methods for system identification associated with damage detection are studied. Development and evaluation of smart structural elements: Devices utilizing the auto-adaptive material such as SMA, PZT, Magneto-Rheological (MR) and Electro-Rheological (ER) Fluids, high tensile strength and ductility concrete, self-repairing material are developed.
Maintaining US Leadership in Aeronautics, NASA Strategic Aeronautics Enterprise Passenger and Crew Safety and Security Increasing demand for operational safety, combined with public awareness of the threat of terrorism and the growth in the volume of air traffic will require improved aviation weather observation dissemination to end users; decision aids on board aircraft to mitigate human error; improved aircraft system reliability through fault tolerance and artificial intelligence; improved systems within aircraft to detect explosives and contraband; and improved aircraft survivability to weapons, electromagnetic impulses, radio frequency interference, and severe weather phenomena. Improved Operating Efficiency and Cost Effectiveness The United States can improve the cost effectiveness and operating efficiency of both civil and military aviation by pioneering the following capabilities: increased automation of aircraft control and air traffic management, including autonomous operations both in the air and on taxiways; uninhabited air vehicles (UAVs) to be used initially for surveillance and weather observation and eventually for aerial combat and cargo transport; tailored materials (designed at the molecular level) and smart materials (able to sense their own conditions) to increase safety, reduce aircraft weight, and to withstand higher engine temperatures; high-efficiency subsonic propulsion systems that provide improved fuel consumption; and finally, miniaturized electronics, sensors, and other nonstructural mechanical components to reduce weight and enable new aircraft and propulsion system designs.
Bi-Morphs, Conducting Polymers One of the most futuristic applications for conducting polymers are 'smart' structures. These are items which alter themselves to make themselves better. An example is a golf club which adapt in real time to a persons tendency to slice or undercut their shots. A more realizable application is vibration control. Smart skis have recently been developed which do not vibrate during skiing. This is achieved by using the force of the vibration to apply a force opposite to the vibration. Other applications of smart structures include active suspension systems on cars, trucks and train; traffic control in tunnels and on roads and bridges; damage assessment on boats; automatic damping of buildings and programmable floors for robotics and AGV's.
Multi-Functional Structures, Foster-Miller (research company in MA) Foster-Miller is working to increase Army ground vehicle engine performance, decrease fuel usage, and increase stealth of these vehicles through the development of a smart, baffleless exhaust system. The Foster-Miller Smart Exhaust System uses smart piezoelectric fibers to convert acoustic energy ("noise") into electrical energy ("heat").
US Army Applications Specific potential military applications of smart structures include shock isolation and machinery vibration, vibration control and stability augmentation systems in rotary wing aircraft to extend structural fatigue life and reliability, barrier structures providing improved protection against CB agents, structural damage detection and health monitoring systems, more accurate rapid fire weapon systems, fire control and battle damage identification, assessment, and control of active, conformal, load–bearing antenna structures, phased arrays, and broadband spiral antenna systems
BAE Systems (British Aerospace,UK) Advanced Technology Centre Case Study Demonstrations of fibre sensors for smart structures and structural usage monitoring 08 Mar 2007 Following the successful maritime demonstration a similar system was fitted to a BAE Systems Jetstream test aircraft and underwent a series of test flights from the Air Systems Warton aerodrome. This work accelerated the development of fibre sensor systems and encouraged by this success, two supplier companies have now been established providing commercial optical sensor equipment.
University of Manchester Dynmamics and Aeroelasticity Special Interest Group • Smart Materials / Structures • Adaptive / Smart Structures • Smart / Self Health Monitoring repairs • Smart fluids for actuator design and shock absorption • Vibration control using smart structures
Commercial Transport Aircraft, various sources • Smart Systems integration and technologies will be key issues to reach these objectives. Smart systems will have a decisive impact on the development of airplane and spacecraft structures, performance monitoring, engine operations, navigation and safety systems. • Figure 2: Remote maintenance based on wireless smart sensors • They enable more precise control of aircraft while reducing the size, mass and power requirements for operational and safety functions as well as energy efficiency. • Translating the aeronautics requirements into the world of smart systems technologies and grouping the various aspects, four major future scenarios can be defined: • The connected aircraft • The intelligent aircraft • The electrical aircraft • The efficient aircraft.
Smart Instruments, Georgia Tech If they are successful, musicians could one day use "smart structures" built into inexpensive acoustic guitars to create sound as rich as that produced today by high quality instruments costing thousands of dollars. The smart structures -- material systems that have the inherent ability to change their mechanical properties -- would also provide a better method for customizing guitars and tuning them for different performance halls. Researchers Steven Griffin (r) and Sathya Hanagud study wave patterns altered by the "smart" materials on the guitar.
Bose Aviation Headset • Contain a sensor and cancelling circuit (inverse of incoming sound, still able to hear 95% of speech range) • Developed for the Rutan/Yeager Voyager flight around the world (both would have been deaf without it) • Coveted by pilots • Cost about $1,000
An active structure consists of a structure provided with a set of actuators and sensors coupled by a controller; if the bandwidth of the controller includes some vibration modes of the structure, its dynamic response must be considered. If the set of actuators and sensors are located at discrete points of the structure, they can be treated separately. The distinctive feature of smart structures is that the actuators and sensors are often distributed and have a high degree of integration inside the structure, which makes a separate modelling impossible. Micromega Dynamics, Belgium
Smart Nanotubes, UCSB The nanotubes are "smart" because they can open or close at the ends, depending on how the researchers manipulate the electric charge on the two components. So in principle, a nanotube could encapsulate a drug or a gene, and then open on command to deliver the cargo where it would have the best effect.
Sensors for Human Health Monitoring, form follows way behind function Dr. Sundaresan Jayaraman, Professor, Atlanta, GA. Wearable Motherboard (Smart Shirt): This invention is a flexible, wearable and comfortable garment with sensors for "unobtrusively" monitoring a variety of vital signs, including heart rate, respiration rate, electrocardiogram (ECG), body temperature, and pulse oximetry (SpO).
Smart Drill, Rambor mining technology The 'Smart' drill machine measures motor speed, drilling distance, motor torque and leg thrust to determine the geological structure of the drilled medium.
Health Monitoring, Vibration Testing, University of Patras, Greece Mode Shifts for Damaged Structure
Alternative Text or Resources This book introduces the enabling concepts that make up the so-called "smart structure" and presents a number of brief case studies to illustrate the applications of these concepts. It examines the domains of the individual technologies and defines the challenges faced by the integrator. The book is particularly effective for the potential system user who needs a good technical general background on the subject and is also useful for students and researchers in contributory technologies who want to better understand the context of their work. Consultants in civil and structural engineering will also find it of interest. Brian Culshaw, Smart Structures and Materials Smart Structures, Nonlinear Dynamics, and Control Daniel J. Inman (Editor), Ardeshir Guran (Editor), Hardcover, Prentice Hall December 1995, List Price $81.00, 9780134344577 (013434457X)
Resources, cont. Encyclopedia of Smart Materials by Mel Schwartz
Journals Smart Structures and Systems Structural Control & Health Monitoring International Journal of Structural Stability and Dynamics
Summary • Smart structures information (and much more) was found by simply typing “smart structures” into “Google” • The point is, smart structures are here to stay • Smart Structures are a global technological issue; term possibly coined in the US, but all nations have embraced the concept and need