Center for Structures in Extreme Environments Haym Benaroya, benaroya@rci. rutgers. edu MAE Open House So. E 12 March 2008
Research Focus of Center • • • Structural modeling Offshore structures • Force modeling Aircraft structures • Uncertainties Lunar and Martian definition structures • Reliability and life Nanostructures estimates 2
Disciplinary Focus of Center Primary • structural dynamics & environmental modeling • multi-disciplinary engineering Secondary • economics and finance • policy • sociology • psychology 3
Nonlinear Nanoresonator Dynamics: Sensors & Mechanisms
Research Focus of Center Aircraft structures 5
Aircraft Structures Small fuselage section between consecutive frames and stringers (SP) Panel of an LD-3 luggage container (LP) SP: Al 2024 -T 3 20 x 8 x 0. 063 in LP: Al 7021 -T 6 59 x 57. 5 x 0. 16 in
Example of Box Shaped Model I LD-3 luggage container after internal bomb blast n 2. 01 m x 1. 57 m x 4 mm (Panel III) n 1. 53 m x 1. 63 m x 4 mm (Panel IV) n Clamped Al 7021 -T 6 Plate Pressure loading of Fleisher (1996)
Elastic Deformation Pattern Elastic sinusoid deformation pattern Assumed form of elastic plate deflection Clamped plate SDOF equation of motion General form of yield criterion
Plastic Deformation Pattern Analytical idealization of experimental profile Experimental deformation profile of Jones et al. (1970) n All energy is dissipated in the edges and five plastic hinges. General equation of motion
Smaller Panel Standard Deviation Bounds Mean deflection of SP subjected to SC with bounds Mean deflection of SP subjected to LC with bounds 10
Larger Panel Standard Deviation Bounds Mean deflection of LP subjected to SC with bounds Mean deflection of LP subjected to LC with bounds 11
Probability of Failure LC/LP SC/SP • Monte Carlo method can also be used to estimate the probability of structural failure. • Based on maximum strain criterion. • All failures for LC/SP case. • No failures for SC/LP case. Probability of failure for SC/SP and LC/LP cases 12
Research Focus of Center Lunar and Martian structures 13
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Extraterrestrial Structures Extraterrestrial structures such as those appropriate for the Moon and Mars present added difficulties due in part to: • the lack of atmosphere • the large distance from safety • often intense radiation • micrometeorites • extreme temperatures and temperature fluctuations
Structural Design of a Lunar Base Layout 16
Research Focus of Center Offshore structures 17
Heidrn Platform Using a technologically innovative compliant tower, the Baldpate Field, on Garden Banks 259/260, was brought on stream in 1998.
Equatorial Guinea • The Okume Complex is comprised of the Okume, Oveng, Ebano and Elon fields which have been developed using a combination of two tension leg platforms and four fixed platforms.
Norway’s Valhall field Denmark's South Arne
Tension Leg Platform (TLP) Ram-Powel TLP in Gulf of Mexico (built in 1997 in 3, 214 ft of water) Schematic of a TLP 21
Schematics of Compliant Towers Articulated Tower Tension Leg Platform 22
Coupled Axial and Transverse Vibration with End Tension • Tower has two degrees of freedom • Tower is extensible • The tower has a Tension applied at the free end • In-plane fluid force is approximated by the Morison equation. 23
Vortex-Induced Oscillations: Analysis and Experiments “Inverted Pendulum Model” • Hollow aluminum tube attached by a leaf spring. • d = 2. 54 cm; l = 128 cm • Mass ratio = 1. 53 • Damping ratio = 0. 054 • fn = 1. 25 Hz • Motion restricted to the cross stream plane • Deflection; qmax ≈ 1. 1° 24
In Closing: Celebration after Rutgers upsets #3 Louisville 28 -25 on 11/9/06
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