VEHICLE TECHNOLOGY DIRECTORATE Crash Simulation of a Vertical Drop Test of a B737 Fuselage Section with Overhead Bins Karen E. Jackson and Edwin L. Fasanella US Army Research Laboratory Vehicle Technology Directorate NASA Langley Research Center Hampton, VA Third Triennial Aircraft Fire and Cabin Safety Conference Atlantic City, New Jersey October 22-25, 2001

In November of 2000, the FAA performed a 30-ft/s vertical drop test of a 10-ft. long fuselage section of a Boeing 737 (B737) transport aircraft The fuselage section was outfitted with two different commercial overhead stowage bins and luggage The objective of the test was to evaluate the dynamic The objective of the test was to evaluate the dynamic response of the overhead bins in a narrow-body response of the overhead bins in a narrow-body transport fuselage section subjected to a severe, but transport fuselage section subjected to a severe, but survivable, impact event survivable, impact event This test also provided a unique opportunity to evaluate This test also provided a unique opportunity to evaluate the capabilities of computational tools for crash the capabilities of computational tools for crash simulation simulation Introduction and Background Information VEHICLE TECHNOLOGY DIRECTORATE

To develop a finite element model of the fuselage section suitable for execution in a crash simulation Perform a crash simulation using the nonlinear, explicit transient dynamic code, MSC.Dytran, and generate pre-test predictions of fuselage and overhead bin dynamic responses Validate the model through extensive analytical and experimental correlation Assess simulation accuracy and suggest changes to the model for improved correlation Objectives VEHICLE TECHNOLOGY DIRECTORATE

Vertical Drop Test of a B737 Fuselage Section Pre-test photograph 10-ft. long section of a B transport aircraft from FS 380 to FS 500, weighing 1, 360-lbs. Six triple-occupant passenger seats with test dummies and mannequins 3,229-lbs. of luggage Two different commercial overhead stowage bins loaded with wood 14-ft. drop test onto wooden platform for 30-ft/s vertical velocity ≈140 channels of data collected at 10,000 samples per second

VEHICLE TECHNOLOGY DIRECTORATE Vertical Drop Test of a B737 Fuselage Section Heath Tecna Overhead Bin Forward FS 400FS 420FS 440FS 460FS 480

VEHICLE TECHNOLOGY DIRECTORATE Vertical Drop Test of a B737 Fuselage Section Hitco Overhead Bin Forward FS 440FS 460FS 480FS 420FS 400

VEHICLE TECHNOLOGY DIRECTORATE Asymmetry in the Test Article Seat rails Seats Rear Front Right Left Floor Plan View Schematic Photograph of the Cargo Door

VEHICLE TECHNOLOGY DIRECTORATE Vertical Drop Test of a B737 Fuselage Section Post-test Photographs Right-side seat failure Asymmetric deformation of the lower fuselage

VEHICLE TECHNOLOGY DIRECTORATE MSC.Dytran Model Development Crash Simulation of the Vertical DropTest of the B737 Fuselage Section Model geometry was developed from hand measurements, i.e. no engineering drawings available Model contains 9, 759 nodes and 13,638 elements, including 9, 322 shell and 4, 316 beam elements Seats, dummies, cameras, luggage, and plywood in bins modeled using concentrated masses Material properties were estimated using engineering judgement Front view of model

VEHICLE TECHNOLOGY DIRECTORATE MSC.Dytran Model of the Heath Tecna Bin Crash Simulation of the Vertical DropTest of the B737 Fuselage Section Three-quarter view Side view Front view

VEHICLE TECHNOLOGY DIRECTORATE MSC.Dytran Model of the Hitco Bin Crash Simulation of the Vertical DropTest of the B737 Fuselage Section Side view Front view Three-quarter view

VEHICLE TECHNOLOGY DIRECTORATE Crash Simulation of the Vertical DropTest of the B737 Fuselage Section Rigid impact surface was added to represent the wooden platform 3 master-surface to slave-node contact surfaces were defined between: - the impact surface and lower fuselage structure - the Heath Tecna bin and the upper fuselage structure - the Hitco bin and the upper fuselage structure The model was executed for 0.2 seconds of simulation time, requiring 36 hours of CPU on a Sun Ultra Enterprise 450 workstation computer MSC.Dytran Model Execution Three-quarter view of model

VEHICLE TECHNOLOGY DIRECTORATE Analytical and Experimental Correlation Acceleration, g Time, s Left outer seat track Left inner seat track Vertical Acceleration Responses of the Left-Side Inner and Outer Seat Track at FS 484

VEHICLE TECHNOLOGY DIRECTORATE Analytical and Experimental Correlation Vertical Acceleration Responses of the Right-Side Inner and Outer Seat Track at FS 484 Acceleration, g Time, s Right outer seat track Right inner seat track

VEHICLE TECHNOLOGY DIRECTORATE Analytical and Experimental Correlation Vertical Velocity Responses of the Left- and Right-Side Outer Seat Track at FS 418 Left outer seat track Right outer seat track Velocity, ft/s Time, s Velocity, ft/s Time, s

VEHICLE TECHNOLOGY DIRECTORATE Analytical and Experimental Correlation Vertical Acceleration Responses of the Left- and Right-Side Lower Side Wall at FS 480 Left-side lower side wall Right-side lower side wall Acceleration, g Time, s Acceleration, g Time, s

VEHICLE TECHNOLOGY DIRECTORATE Axial Force Responses of the Vertical Support Rods HT-1 and HT-3 of the Heath Tecna Bin Axial Force, lbs. Time, s Axial Force, lbs. Time, s Forward support rod, HT-1 Rear support rod, HT-3 Measured tensile failure load = 1,656 lbs.

VEHICLE TECHNOLOGY DIRECTORATE Axial Force Responses of the.616-in. Diameter Support Rods H-1 and H- of the Hitco Bin Axial Force, lbs. Time, s Axial Force, lbs. Time, s Support rod, H-1 Support rod, H-2 Measured tensile failure load = 5,350 lbs.

VEHICLE TECHNOLOGY DIRECTORATE Analytical and Experimental Correlation Predicted Structural Deformation Time = 0.0 s Time = 0.06 sTime = 0.09 s Time = 0.12 sTime = 0.15 s Time = 0.18 s

Concluding Remarks A finite element model of the B737 fuselage section with overhead bins and luggage was developed and pre-test predictions of fuselage and bin responses were generated The model was generated from hand measurements of fuselage geometry (no engineering drawings were available) Predicted floor-level acceleration responses compared favorably with experimental data with peak acceleration values with ±5-g Integrated velocity comparisons indicate that the model is too stiff and removes velocity more quickly that the test Deformed plots of the model indicate excessive deformation of the lower fuselage structure into the cargo hold VEHICLE TECHNOLOGY DIRECTORATE

Ongoing Research VEHICLE TECHNOLOGY DIRECTORATE Incorporate platform model Model luggage physically using solid elements Add rotation springs at joints between bin linkages Modify material properties Rediscretize model in certain regions Examine the effect of the contact penalty factor Suggested Model Improvements Fuselage Model with Platform Fuselage Model with Luggage

Acknowledgements VEHICLE TECHNOLOGY DIRECTORATE This research was performed under an Inter Agency Agreement DTFA03-98-X-90031, established in 1998, between the US Army Research Laboratory, Vehicle Technology Directorate and the FAA William J. Hughes Technical Center. The technical support and contributions provided by Gary Frings, Tong Vu, and Allan Abramowitz of the FAA are gratefully acknowledged.