Model for Texas Transportation Institute Test 7069-13

TTI Test 7069-13 involved a 1979 International TranStar 4200 tractor with a 1977 Pullman van-trailer ballasted to 50,050 lb (22723 kg) impacting the barrier at 51.4 miles per hour (82.7 km/hr) and 16.2 degrees. The installation length of the barrier was 100 ft (30 m), and the impact point was 24 ft (7.3 m) from the upstream end.

The tractor-semitrailer FE model used for simulating the TTI test 7069-13 includes additional input files (nodesin.k and dynain.k) that contain necessary node and element information for gravity initialization of the model prior to start of the analysis. One important note about the nodesin.k file is that this file replaces all node definitions in all the input *.k files when the gravity initialization approach is used. The original node definitions are still in the input files; they are defined at the end of the files, and are commented out by the insertion of a *END right before the node definitions. This provides the user an easy way to reinstate the original node definitions in any input file by removing the *END line before the node definitions if the user desires to run a simulation using this model without gravity initialization.

Input Files for the Day Cab Tractor (wheelbase 194in) with 45-foot Trailer Model

• 00MainGravInit.k This is the input file that is submitted to LS-Dyna for analysis. It uses the *INCLUDE command to combine all the input files for the model.
• 01a_Trac_Day_10-0621_TTI.k The finite element model of a Freightliner FLD120 tractor geometrically modified to be the Day Cab tractor from the TTI test 7069-13. All nodes, elements, materials, connections, etc. for the tractor are included in this file.
• 01b_Intial-stress_Tractor.k File containing initial stress state for the front leaf springs of the tractor to account for equilibrium load on the leaf spring components under gravity loading. Without this file, the tractor would displace significantly under gravity load, altering the center of gravity and bumper height.
• 01c_AirRide20psi.k Part, Section and Material definition for the discrete element model of the Airide suspension with properties corresponding to 20 psi internal pressure for a tractor-only simulation.
• 01c_AirRideTractor45psi.k Part, Section and Material definition for the discrete element model of the Airide suspension with properties corresponding to 45 psi internal pressure. Used in tractor-semitrailer model for trailer ballasted to 50,000 lbs (22,700 kg).
• 02a_SemiTrailer45_10-0621_TTI7069-13.k The finite element model of 45-ft Stoughton semitrailer. All nodes, elements, connections, etc. for the trailer are included in this file.
• 02c_AirRideTrailer20psi.k Part, Section and Material definition for the discrete element model of the Airide suspension with properties corresponding to 20 psi internal pressure for an empty trailer.
• 02c_AirRideTrailer45psi.k Part, Section and Material definition for the discrete element model of the Airide suspension with properties corresponding to 45 psi internal pressure.
• 02b_TrailerMaterials_2010-0217.k Material database for the semitrailer
• 03Tractor2Trailer_connection.k Creates a spherical joint connection between the trailer kingpin and the tractor fifth-wheel. Also, defines contact between the kingpin box and fifth-wheel.
• 05NJB-Ballast2-foam11b.k Ballast for the trailer model with mass of 10,134 kg
• 05Contact11.k Tie contact between ballast bolts and trailer floor, the ballast parts with the trailer and ballast self-contact.
• 15TL-3_7069-13_Bridge_Parapet_Elastic2.k Impacted bridge parapet barrier
• 15contact-tractor2010-0323.k Contact between tractor and median barrier
• 15contact-trailer2.k Contact between trailer and median barrier
• 20control1.k Defines *CONTROL, *DATABASE, *CONTACT_INTERIOR for the entire model. This file is always read in last and overrides any previous definitions of these parameters from the earlier input files.
• dynain.k Gravity-initialized stresses for the entire FE model
• nodesin.k Gravity-initialized nodal locations for the entire FE model

Simulation

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