2012 MATC Spring Lecture Series: Karla Lechtenberg
Download as PPTX, PDF0 likes137 views
This document summarizes research evaluating the crash performance of work zone devices under new MASH testing standards. Analytical studies and 8 full-scale crash tests were conducted. Key findings include: - 3 of 8 systems passed MASH criteria, with pickup truck tests failing 3 of 4 systems and small car tests failing 2 of 4 systems. - Parameters like sign material, mast height, and orientation were identified as important for failure, especially with pickup trucks. - Recommendations are provided to guide designers on parameters to avoid for meeting MASH.
![Midwest Roadside Safety Facility
Vehicle Parameters
Vehicle
Parameter 820C 1100C 2000P 2270P
Hood Length [in.] 31.5 34.7 45.1 41
Height to bumper [in.] 18 18 26 27
Height to roof [in.] 58 55.5 73.3 75.8
Windshield Angle 39° 32° 42° 34°
Windshield Length [in.] 30.2 28.1 26.8 31.5](https://image.slidesharecdn.com/lechtenberg-matc-160505170245/85/2012-MATC-Spring-Lecture-Series-Karla-Lechtenberg-11-320.jpg)
2012 MATC Spring Lecture Series: Karla Lechtenberg
- 1. SAFETY PERFORMANCE OF WORK- ZONE DEVICES UNDER MASH TESTING Karla Lechtenberg Midwest Roadside Safety Facility Nebraska Transportation Center University of Nebraska-Lincoln June 2012
- 2. Midwest Roadside Safety Facility Outline • 3-5 learning objectives…
- 3. Midwest Roadside Safety Facility Background • NCHRP Report No. 350 • Crash test conditions at Test-Level 3 (TL-3) – 1,808-lb small car (820C) • 22 mph • 62 mph – Normally tested at 0°and 90° orientations – 4,409-lb pickup truck (2000P) not used 0°Orientation 90°Orientation
- 4. Midwest Roadside Safety Facility Problem Statement • Work zone signs only tested with small car • Systems tuned for small car • Simulated pickup truck tests indicated failure • MASH requires pickup truck testing • Current WZ sign systems may not meet MASH
- 5. Midwest Roadside Safety Facility Pickup Truck Bogie Testing Potential for sign to penetrate windshield 5
- 6. Midwest Roadside Safety Facility Research Objectives • Determine if current WZ sign systems meet MASH • Identify WZ hardware parameters that increase propensity for failure • Provide guidelines and recommendations
- 7. Midwest Roadside Safety Facility Research Plan • Analytical study – Evaluate all full-scale tests – Study individual hardware parameters – Select work zone sign systems with a propensity for failure • Conduct 4 full-scale tests – 2 small car and 2 pickup truck – 2 systems per test
- 8. Midwest Roadside Safety Facility Previous Testing • Small Car Crash Tests – 157 full scale • Pickup Truck Tests – 157 full scale – 18 bogie tests
- 9. Midwest Roadside Safety Facility System Parameters
- 10. Midwest Roadside Safety Facility Methods of Failure • Severe Windshield Cracking and Failure • Windshield Indentation ≥ 3 inches • Windshield Penetration • Other Occupant Compartment Penetration • Roof Deformation ≥ 4 inches
- 11. Midwest Roadside Safety Facility Vehicle Parameters Vehicle Parameter 820C 1100C 2000P 2270P Hood Length [in.] 31.5 34.7 45.1 41 Height to bumper [in.] 18 18 26 27 Height to roof [in.] 58 55.5 73.3 75.8 Windshield Angle 39° 32° 42° 34° Windshield Length [in.] 30.2 28.1 26.8 31.5
- 12. Midwest Roadside Safety Facility Predicted Performance • Sign trajectory • Vehicle geometry • Classified by risk of failure – 1: 75-100% – 2: 50-75% – 3: 25-50% – 4: 0-25%
- 13. Midwest Roadside Safety Facility Important Parameters for Failure ≥50% of systems with a parameter were predicted to fail for either vehicle • Both Vehicles – Height to top of mast – Sign panel material – Mast stages – Mast material – Flag staff material – Orientation • Car Only – Height to top of flags – Sign-locking mechanism • Truck Only – Base layout 1
- 14. Midwest Roadside Safety Facility System Analysis • Systems that were predicted to fail MASH by: – Windshield penetration – Other occupant compartment penetration – Roof deformation • Analyzed systems based on combinations of important parameters
- 15. Midwest Roadside Safety Facility Critical Parameters for 2270P Test Failure Low-Mounting Height • X-footprint base – Spring base – Aluminum and vinyl panel – 0 and 90 degree orientations – With flags • Parallel Dual Uprights – Aluminum panel – 0 degree orientation – Without flags High-Mounting Height • X-footprint base – Spring base or slipbase – Aluminum panel – 90 degree orientation – With flags • Parallel Dual Uprights – Aluminum panel – 90 degree orientation – Without flags
- 16. Midwest Roadside Safety Facility Critical Parameters for 1100C Test Failure Low-Mounting Height • X-footprint base – Spring base – Flags – Aluminum panel @ 0 degree orientation – Vinyl panel @ 90 degree orientation Low-Mounting Height • Parallel Dual Uprights – Aluminum Panel – 0 and 90 degree orientations – No flags
- 17. Midwest Roadside Safety Facility Crash Testing Requirements • MASH Test Level 3 Criteria – 5,000 lb pickup truck, 62 mph – 2,425 lb small passenger car, 62 mph • Evaluation Criteria – Structural Adequacy – Occupant Risk – Vehicle Trajectory
- 18. Midwest Roadside Safety Facility Full-Scale Crash Testing • 4 small car tests at 62 mph (Test Designation No. 3-71) • 4 pickup truck tests at 62 mph (Test Designation No. 3-72)
- 19. Midwest Roadside Safety Facility WZ09-1A
- 20. Midwest Roadside Safety Facility WZ09-1A • FAILURE
- 21. Midwest Roadside Safety Facility WZ09-1B
- 22. Midwest Roadside Safety Facility WZ09-1B • FAILURE
- 23. Midwest Roadside Safety Facility WZ09-2A
- 24. Midwest Roadside Safety Facility WZ09-2A • PASS
- 25. Midwest Roadside Safety Facility WZ09-2B
- 26. Midwest Roadside Safety Facility WZ09-2B • FAILURE
- 27. Midwest Roadside Safety Facility WZ09-3A
- 28. Midwest Roadside Safety Facility WZ09-3A • FAILURE
- 29. Midwest Roadside Safety Facility WZ09-3B
- 30. Midwest Roadside Safety Facility WZ09-3B • PASS
- 31. Midwest Roadside Safety Facility WZ09-4A
- 32. Midwest Roadside Safety Facility WZ09-4A • FAILURE – Windshield penetration – Floorboard penetration
- 33. Midwest Roadside Safety Facility WZ09-4B
- 34. Midwest Roadside Safety Facility WZ09-4B • PASS
- 35. Midwest Roadside Safety Facility Test Summary • 3 of the 8 systems passed MASH evaluation criteria – 3 of the 4 systems failed with the pickup truck – 2 of the 4 systems failed with the small car • Comparing systems with similar parameters can be difficult
- 36. Midwest Roadside Safety Facility Important for MASH Failure Parameter Pickup Truck Small Car Sign Panel Material Aluminum Aluminum Height to Top of Mast 75-135 in. 59-110 in. Presence of Flags Without Flags With and Without Flags Orientation Both 0 and 90 degrees Both 0 and 90 degrees Sign Locking Mechanism NA Rigid Brackets Base Layout X-footprint NA Designers cautioned against using important parameters
- 37. Midwest Roadside Safety Facility Design Aides 1Breakaway Mechanism Height: Low ≤ 24”, High > 24” or no breakaway mechanism 2Chance of Failing MASH: 1 - 75 to 100%, 2 – 50 to 75%, 3 – 25 to 50%, 4 – 0 to 25%, 5 – Unknown 1 2
- 38. Slide design © 2009, Mid-America Transportation Center. All rights reserved. Center for Transportation Research Education at Iowa State Mid-America Transportation Center Private Industry For more information, the report can be found: http://www.intrans.iastate.edu/smartwz/details.cfm?proje ctID=82 CREDITS