1 Center for Structures in Extreme Environments MAE Open House SoE 12 March 2008 Haym Benaroya,

2 Research Focus of Center Offshore structures Aircraft structures Lunar and Martian structures Nanostructures Structural modeling Force modeling Uncertainties definition Reliability and life estimates

3 Primary structural dynamics & environmental modeling multi-disciplinary engineering Secondary economics and finance policy sociology psychology Disciplinary Focus of Center

4 Nonlinear Nanoresonator Dynamics: Sensors & Mechanisms

5 Research Focus of Center Aircraft structures

6 Aircraft Structures Panel of an LD-3 luggage container (LP) Small fuselage section between consecutive frames and stringers (SP) SP: Al 2024-T3 20 x 8 x in LP: Al 7021-T6 59 x 57.5 x 0.16 in

m x 1.57 m x 4 mm (Panel III) 1.53 m x 1.63 m x 4 mm (Panel IV) Clamped Al 7021-T6 Plate Pressure loading of Fleisher (1996) LD-3 luggage container after internal bomb blast Example of Box Shaped Model I

8 Elastic Deformation Pattern Elastic sinusoid deformation pattern Clamped plate SDOF equation of motion General form of yield criterion Assumed form of elastic plate deflection

9 Experimental deformation profile of Jones et al. (1970) General equation of motion Analytical idealization of experimental profile Plastic Deformation Pattern All energy is dissipated in the edges and five plastic hinges.

10 Smaller Panel Standard Deviation Bounds Mean deflection of SP subjected to SC with bounds Mean deflection of SP subjected to LC with bounds

11 Mean deflection of LP subjected to SC with bounds Mean deflection of LP subjected to LC with bounds Larger Panel Standard Deviation Bounds

12 Probability of Failure 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 SC/SP LC/LP

13 Research Focus of Center Lunar and Martian structures

14

15 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

16 Base Layout Structural Design of a Lunar Base

17 Research Focus of Center Offshore structures

18 Heidrn Platform Using a technologically innovative compliant tower, the Baldpate Field, on Garden Banks 259/260, was brought on stream in 1998.

19 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.

20 Denmark's South Arne Norway’s Valhall field

21 Ram-Powel TLP in Gulf of Mexico (built in 1997 in 3,214 ft of water) Schematic of a TLP Tension Leg Platform (TLP)

22 Schematics of Compliant Towers Articulated TowerTension Leg Platform

23 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.

24 “Inverted Pendulum Model” Hollow aluminum tube attached by a leaf spring.Hollow aluminum tube attached by a leaf spring. d = 2.54 cm; l = 128 cmd = 2.54 cm; l = 128 cm Mass ratio = 1.53Mass ratio = 1.53 Damping ratio = 0.054Damping ratio = f n = 1.25 Hzf n = 1.25 Hz Motion restricted to the cross stream planeMotion restricted to the cross stream plane Deflection;  max ≈ 1.1°Deflection;  max ≈ 1.1° Vortex-Induced Oscillations: Analysis and Experiments

25 In Closing: Celebration after Rutgers upsets #3 Louisville on 11/9/06