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International Aircraft Fire and Cabin Safety Research Nov. 16 - 20, 1998. Application of Finite Element Dynamic Simulation to Airplane Cabin in Air Turbulence Vahid Motevalli and Ahmad Noureddine. Transportation Research Institute The George Washington University. Acknowledgement.
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International Aircraft Fire and Cabin Safety Research Nov. 16 - 20, 1998 Application of Finite Element Dynamic Simulation to Airplane Cabin in Air TurbulenceVahid Motevalli and Ahmad Noureddine Transportation Research InstituteThe George Washington University
Acknowledgement • Robert L. Frantz , AirLine Pilots Association (ALPA) • Dhafer Marzogui of the National Crash Analysis Center (NCAC) at GW
The GW Aviation Institute Established in March of 1998 • Three collaborating institute • The GW Transportation Research Institute • Institute for Crisis, Disaster & Risk Management • International Institute for Travel and Tourism • Research in all aspects of Aviation Safety and Security • Certificate Program in Aviation Safety and Security Management
Background • Between 1980-1997, there has been 3 fatalities and 629 injuries due to turbulence (ATA) • Competing and contributing phenomena: • Increased flights, passenger loads • Reducing fatal accident rates of the first kind (CFIT, in-flight Human Errors, …) • High on-time performance pressures (hub & spoke operations, competitions, etc.) • Increased need for commuter flights (smaller jets and turbo-props and jets) • Increase in low-fatality (non-haul loss) accident rate, e.g. turbulence, crash landings. More attention must be paid to injuries to passengers and flight attendants.
Candidate Airplane Incident Categories for Computer Simulations Bomb • In-Flight • Fire and Explosion • Structural Failure • Turbulence Mechanical/Electrical Component Failure • Crash/Post-crash • Occupant survivability (impact) • Crashworthiness - Component failure (fuel tank, seats, over-head bins, etc..) • Fire/explosion • Hull breach • Occupant injuries and egress
Predictive Analytical/Computational Tools Needed to Solve these Problems • Current Capabilities • Component structural analysis (many tools, accepted) • Composites analysis (limited) • Computational Fluid Dynamics, (CFX4.2, KIVA3V, acceptable?) • Dynamic structural analysis (LS-DYNA3D, etc., acceptable) • Future Vision: 21st Century Coupled structural/fluid/combustion modeling capability to perform comprehensive simulation of incidents, tests and performance evaluation for Enhancement of Airplane Safety/Survivability/Airwothiness /Crashworthiness
Airplane Simulations • Structural Construction of a “Generic” Wide-Body Commercial Passenger Airplane • “Virtual Reality” View of the Entire Plane • Incident and Test Simulation • Landing gear failure
Airplane Simulations • Structural Construction of a “Generic” Wide-Body Commercial Passenger Airplane • “Virtual Reality” View of the Entire Plane • Incident and Test Simulation • Landing gear failure • Impact landing - obstructed runway (similar to CIDE)
Airplane Simulations • Structural Construction of a “Generic” Wide-Body Commercial Passenger Airplane • “Virtual Reality” View of the Entire Plane • Incident and Test Simulation • Landing gear failure • Impact landing - obstructed runway (similar to CIDE) • Fuselage drop tests with “occupants”
Demonstration of Finite Element Simulation of Air Turbulence • Actual Wide-body passenger airplane geometry • Generic structural elements and connections • Detailed Finite Element model of the fuselage section • Hybrid III dummy models with and without restrain • Sample turbulence data, 3-axis acceleration, pitch, yaw and roll
Simulation of Air Turbulence Total Number of Elements: 50,000 2 Hybrid III Dummy models: 14,000 elements each Turbulence duration simulated: 2.5 seconds Input: longitudinal, lateral, and vertical acceleration plus pitch and roll Total run time: 30 hours (multiple processors) Most dummy parts in this model are rigid except for the head skin and the neck to reduce the run time. Airplane cabin parts were also rigidized for the same reason. Time step was maximized.
Potential uses of Finite Element Simulation of Aircraft in Turbulence • Passenger education for in-flight seat-belt use to avoid turbulence-induced injuries • Structural Evaluation of overhead bins during severe turbulence and dynamic impact • Evaluation of interior panel integrity • Evaluation of Bulk-head occupant injury reduction approaches • Occupant safety issues (falling luggage, child safety, seat design, etc.)
Conclusions • HIC number may not be a right measure for this type of head impact scenario • Force of impact is certain to cause neck injuries. • Tremendous potential to use finite element simulation for aircraft occupant safety issue • A large number of issues such as: • passenger compliance with seatbelt use • child safety in turbulence • overhead bin performance • unsecured objects.