Thrie-Beam Retrofit Phase 2 – Application of a New Design without a Curb for MASH TL-3 and Performance and Improvements for MASH TL-4 (TTI-619601, T1969-AE)
TTI Research Supervisor:
William F. Williams, P.E.
Texas A&M Transportation Institute
TAMU 3135
College Station, Texas 77843-3135
(979) 845-8955 [email protected]
Pooled Fund Technical Representative:
Carlos Torres, P.E.
Roadside Safety Engineer
Michigan Dept. of Transportation
(517) 335-2852 [email protected]
ABSTRACT
Engineering Analyses & Detailing of a new retrofit designs for MASH TL4 was developed for this project. This new design utilized a HSS 10x4x3/8 tube mounted to the top of the Thrie-beam Retrofit Design previously tested to MASH TL-3 using post spacing of 3’-1 1 /2” on centers. The total height of this design was 43 inches. LS-DYNA simulations using the MASH TL-4 Vehicle (SUT) were successful. Engineering strength analyses were performed on the new retrofit design. The calculated strength was 100 kips at 30 inches height. This new design meets the strength requirements of MASH TL-4 (80 kips at 30 inches height). The new design shown herein is recommended for MASH TL-4 applications. TTI has prepared engineering details of this recommended design retrofit. The tested design is recommended for MASH TL-4. Simulations of As-Tested Design without a Curb for MASH TL-3 were performed. The As-Tested design without a curb is recommended for MASH TL-3. No design modifications were needed for MASH-TL-3. Simulations were performed on the as-tested Design with a Curb for MASH TL-4. Due to strength and instability of the SUT, this design (As-Tested for MASH TL-3 under TTI Project 615131) is not recommended for MASH TL-4.
