Development, Crash Testing, and Evaluation of Steel-Post Trailing-End Guardrail Anchorage System

2021 ◽  
pp. 036119812110319
Author(s):  
Mojdeh Asadollahi Pajouh ◽  
Karla Lechtenberg ◽  
Ronald Faller ◽  
Tewodros Yosef
Keyword(s):  
Safety Performance ◽  
Reverse Direction ◽  
Roadside Safety ◽  
Safety Requirements ◽  
Component Testing ◽  
Crash Testing ◽  
Anchorage System ◽  
Structural Capacity ◽  
Departments Of Transportation ◽  
Crash Tests

Trailing-end guardrail anchorage systems are widely used by most state departments of transportation (DOTs) and generally consist of simple adaptations of crashworthy end terminals. The safety performance and structural capacity of these trailing-end anchorage systems, when reverse-direction impacts occur near the end, is imperative in crashworthiness of guardrail systems. In 2013, a non-proprietary trailing-end anchorage system with a modified breakaway cable terminal (BCT) was developed by the Midwest Roadside Safety Facility (MwRSF) for the Midwest Guardrail System (MGS). Although this trailing-end guardrail anchorage system adequately met the Manual for Assessing Safety Hardware (MASH) TL-3 safety requirements, the use of two breakaway wood posts was deemed by some users to have several drawbacks. Thus, there was a critical need to develop a non-wood option to anchor the downstream end of the W-beam guardrail system, which led to the need to develop a steel-post trailing-end guardrail anchorage system for use with the MGS. Following the design and component testing of such a system, two full-scale crash tests were performed according to the MASH 2016 test designation nos. 3-37a and 3-37b. In the first test, a 2270P pickup truck struck the guardrail system and was adequately contained and redirected. In the second test, an 1100C small car struck the barrier and safely gated through the barrier. Both tests were deemed acceptable according to TL-3 safety criteria in MASH 2016. Recommendations are provided for the installation of a steel-post trailing-end guardrail anchorage system when used in combination with MGS.

scholarly journals Two Test Level 4 Bridge Railing and Transition Systems for Transverse Timber Deck Bridges

2000 ◽  
Vol 1696 (1) ◽  
pp. 334-351 ◽  
Author(s):  
Ronald K. Faller ◽  
Michael A. Ritter ◽  
Barry T. Rosson ◽  
Michael D. Fowler ◽  
Sheila R. Duwadi
Keyword(s):  
Forest Products ◽  
Service Level ◽  
Safety Performance ◽  
Performance Criteria ◽  
Transition Systems ◽  
Roadside Safety ◽  
Safety Standards ◽  
Crash Tests ◽  
Test Level ◽  
The U.S

The Midwest Roadside Safety Facility, in cooperation with the Forest Products Laboratory, which is part of the U.S. Department of Agriculture’s Forest Service, and FHWA, designed two bridge railing and approach guardrail transition systems for use on bridges with transverse glue-laminated timber decks. The bridge railing and transition systems were developed and crash tested for use on higher-service-level roadways and evaluated according to the Test Level 4 safety performance criteria presented in NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features. The first railing system was constructed with glulam timber components, whereas the second railing system was configured with steel hardware. Eight full-scale crash tests were performed, and the bridge railing and transition systems were acceptable according to current safety standards.

Design and Validation of a 30,000 kg Heavy Goods Vehicle Using LS-DYNA

2005 ◽  
Author(s):  
Ali O. Atahan ◽  
Guido Bonin ◽  
Mustafa El-Gindy
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Crash Test ◽  
Roadside Safety ◽  
Software Technology ◽  
Crash Testing ◽  
Steering Mechanism ◽  
Technology Corporation ◽  
Crash Tests

Extraordinary developments in virtual crash testing research have been achieved during the past decade. Advancements in hardware and software technology along with improvements in computation mechanics and increased number of full-scale crash tests contributed positively to the development of more realistic finite element models. Use of complex finite element codes based on computational mechanics principles allowed the virtual reproduction of real world problems. Regarding roadside safety, the design phase was, until now, based on the use of simplified analysis, unable to describe accurately the complexity of vehicle impacts against safety hardware. Modeling details, such as geometry, constitutive laws of the materials, rigid, kinematic and other links between bodies, definition and characterization of contact surfaces are necessary to build an accurate finite element model for an impact problem. This set of information is needed for each different body involved in the event; making the development of a complete model very much demanding. Once a part (subset) of the entire model has been accurately validated against real experimental data, it can be used again and again in other analogous models. In this paper, finite element model of a unique Heavy Goods Vehicle (HGV) was developed and partially validated using actual crash test data. Development of this particular vehicle model was important since this vehicle is extensively used in Europe to test the structural adequacy of high containment level (H4a) safety barriers according to EN 1317 standard. The HGV model studied reproduces a FIAT-IVECO F180 truck, a vehicle with 4 axles and a mass of 30,000 kg when fully loaded. The model consisted of 12,337 elements and 11,470 nodes and was built for and is ready to use with LS-DYNA finite element code from Livermore Software Technology Corporation. Results of the validation study suggest that the developed HGV model shows promise and can be used in further studies with confidence. Improvements such as, steering mechanism in front axes and suspension system is currently underway to make model more realistic.

Enhanced MASH TL-3 Short-Radius System: Promising Design to Accommodate Flat Terrain and Ditches

2018 ◽  
Vol 2672 (39) ◽  
pp. 155-165
Author(s):  
Akram Y. Abu-Odeh ◽  
Roger P. Bligh ◽  
Christopher Lindsey ◽  
Wade Odell
Keyword(s):  
Impact Angle ◽  
Roadside Safety ◽  
Flat Terrain ◽  
Crash Testing ◽  
Geometrical Constraints ◽  
Level 3 ◽  
Curved Section ◽  
National Cooperative ◽  
The Impact ◽  
Crash Tests

A challenging guardrail installation situation presents itself when two roadways intersect. Combining the guardrails from intersecting roadway results in what is commonly known as a short radius or T-intersection. It is difficult if not physically impossible to provide the required tensile capacity to the geometrical constraints of the curved section. Researchers and practitioners in the roadside safety area have been investigating the short-radius issue for many years. Investigators conducted numerous crash tests for different short-radius guardrail designs, yet none of those designs passed the National Cooperative Highway Research Program (NCHRP) Report 350 Test Level 3 (TL-3) criteria. In 2009, the crash testing guidelines were updated in the Manual for Assessing Safety Hardware (MASH). MASH guidelines increased the impact severity for TL-3 tests over those in NCHRP 350. This paper presents a MASH TL-3 short-radius design that was successfully crash tested for both a flat terrain and a 3H:1V sloped terrain behind the installation. The impact conditions adopted from the MASH terminal/crash cushion matrix were MASH 3-33, 3-32, 3-31, and 3-35 for the flat terrain. Additionally, a slightly modified design that was installed in front of a 3H:1V slope was successfully evaluated using MASH 3-33 and 3-32 test conditions. These tests used a 25° impact angle since it was shown to be more critical for installation during simulation of the system.

FEA Design and Crashworthiness Evaluation of a 31-Inch W-Beam Guardrail System for Placement on a 3H:1V Sloped Terrain Configuration

2016 ◽  
Author(s):  
Chiara Silvestri Dobrovolny ◽  
Dusty R. Arrington ◽  
Nathan Schulz ◽  
Connie Xavier
Keyword(s):  
Risk Factors ◽  
American Association ◽  
Evaluation Criteria ◽  
Safety Evaluation ◽  
State Highway ◽  
Crash Testing ◽  
Structural Capacity ◽  
Federal Highway ◽  
Impact Simulations ◽  
Departments Of Transportation

The purpose of this research was to develop a 31-inch (787 mm) W-beam guardrail system to be placed with a 3H:1V slope in front of the barrier. The structural capacity and the occupant risk factors of such a proposed guardrail system were evaluated with respect to the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) TL-3 criteria. Finite element computer models of new guardrail designs for evaluation when placed on a 3H:1V sloped terrain configuration were developed and impact simulations were conducted to support their evaluation according to MASH standards evaluation criteria. Three barrier designs for placement on a 3H:1V slope were suggested for evaluation through predictive computer simulations. All systems appear to be crashworthy and likely to pass safety evaluation criteria required for MASH. Depending on the desired system post distance location from the 3H:1V slope break, the researchers recommend evaluation of selected design through full-scale crash testing according to MASH TL-3 criteria. The information compiled from this research will provide the Federal Highway Administration (FHWA) and State Departments of Transportation with a W-beam guardrail design as a crashworthy system to be placed with a 3H:1V slope in front of a barrier.

NCHRP Report 350 Compliance Tests of the ET-2000

1996 ◽  
Vol 1528 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Hayes E. Ross ◽  
Wanda L. Menges ◽  
D. Lance Bullard
Keyword(s):  
Evaluation Criteria ◽  
Passenger Car ◽  
Roadside Safety ◽  
Impact Performance ◽  
Crash Testing ◽  
Level 3 ◽  
New Guidelines ◽  
Safety Features ◽  
The Impact ◽  
Crash Tests

The ET-2000 is one of the end treatments currently approved for use with W-beam guardrail systems. The ET-2000 has successfully met all evaluation criteria set forth in NCHRP Report 230. However, with the adoption of NCHRP Report 350 by FHWA as the official guidelines for crash testing of roadside safety features, it became necessary to reevaluate the ET-2000 to the new guidelines. It is noted that one of the design test vehicles specified in NCHRP Report 230, the 2044-kg passenger car, was replaced by a 2000-kg pickup truck (2000P) under NCHRP Report 350 guidelines. The purpose of the crash tests was to evaluate the ET-2000 according to NCHRP Report 350 guidelines. The ET-2000 met NCHRP Report 350 criteria for Performance Level 3 without any design modifications. All findings in this study demonstrate that the impact performance of the ET-2000 was satisfactory.

Sequential Kinking and Flared Energy-Absorbing End Terminals for Midwest Guardrail System

2005 ◽  
Vol 1904 (1) ◽  
pp. 46-53
Author(s):  
Robert W. Bielenberg ◽  
Dean L. Sicking ◽  
John R. Rohde ◽  
John D. Reid
Keyword(s):  
Center Of Gravity ◽  
Full Scale ◽  
Roadside Safety ◽  
Safety Requirements ◽  
Energy Absorbing ◽  
Crash Tests ◽  
High Center

The Midwest guardrail system (MGS), developed at the Midwest Roadside Safety Facility, was designed to improve the performance of traditional strong-post, W-beam guardrail systems. These improvements include decreasing the potential for rollover with high center-of-gravity vehicles, decreasing the potential for rail rupture at the splice locations, and decreasing the sensitivity of the system to the installation rail height. However, safe guardrail termination options for the MGS must be developed before the system can be implemented on the roadside. Two end terminal designs, the sequential kinking terminal (SKT) and the flared energy-absorbing terminal (FLEAT), were partially redesigned and crash tested in conjunction with the MGS according to NCHRP Report 350 criteria. The new versions of the terminals were named the SKT-MGS and the FLEAT-MGS to designate them for use with the MGS. To evaluate the performance of the terminals with the MGS, a series of four full-scale crash tests was conducted: two redirection tests, NCHRP Report 350 Test Designations 3–34 and 3–35, and two head-on impacts, Test Designations 3–30 and 3–31. The results from the four crash tests were found to meet all relevant safety requirements. The SKT-MGS and FLEAT-MGS end terminals are the first successfully tested end terminals for use with the MGS.

Dynamic Evaluation and Implementation Guidelines for a Nonproprietary W-Beam Guardrail Trailing-End Terminal

2013 ◽  
Vol 2377 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Mario Mongiardini ◽  
Ronald K. Faller ◽  
John D. Reid ◽  
Dean L. Sicking
Keyword(s):  
Safety Performance ◽  
Crash Test ◽  
Impact Location ◽  
Close Proximity ◽  
Level 3 ◽  
Implementation Guidelines ◽  
Potential Risks ◽  
Departments Of Transportation ◽  
Crash Tests ◽  
Test Level

Most state departments of transportation use simple adaptations of crashworthy guardrail end terminals, which typically include breakaway posts and an anchor cable, for downstream anchorage systems. The guardrail safety performance for vehicular impacts occurring in close proximity to these simplified, downstream anchorage systems is not well known. Further, the length of need (LON) for the downstream end of these systems has yet to be adequately determined. This research project assessed the safety performance of the Midwest Guardrail System (MGS) for impacts occurring in close proximity to a nonproprietary, trailing-end guardrail terminal under the Test Level 3 conditions of the Manual for Assessing Safety Hardware. The two research objectives were to (a) determine the end of the LON for impacts with light pickup trucks and (b) investigate potential risks for a small passenger car to become unstable when striking the downstream end of the MGS anchored by the nonproprietary, trailing-end terminal. Numerical simulations were carried out to identify the most critical impact location for the 1100C small car and the end of the LON for the 2270P pickup truck. In full-scale crash tests, considerable snag of the 1100C vehicle occurred; however, occupant risk values and vehicle stability were within acceptable limits. The crash test with the 2270P pickup indicated that the end of the LON was located at the sixth post from the downstream-end post. Guidelines were proposed for installing the MGS to shield hazards in close proximity to the tested nonproprietary, trailing-end terminal.

Critical Impact Points for Transitions and Terminals

2002 ◽  
Vol 1797 (1) ◽  
pp. 105-112
Author(s):  
Roger P. Bligh ◽  
King K. Mak
Keyword(s):  
Safety Performance ◽  
Worst Case ◽  
Roadside Safety ◽  
Simulation Techniques ◽  
Crash Testing ◽  
Families Of Curves ◽  
Impact Location ◽  
Safety Features ◽  
Computer Simulation Techniques ◽  
Selection Of

Guidelines for evaluating the safety performance of roadside safety features generally recommend that a worst case or critical impact point (CIP) be selected for crash testing. NCHRP Report 350 presents families of curves that can be used to determine the CIP for a transition section. However, these curves have been observed to overestimate the stiffness of a transition system and provide CIP values closer to the more rigid system of the transition (e.g., bridge rail end) than appropriate. New CIP selection curves for transitions are presented. A procedure is provided to aid in determining the CIP for transition sections with multiple rail elements or variations in post strength and post spacing. Various existing and theoretical transitions systems with wide-ranging combinations of beam and post strengths were used to validate the curves. The newly developed CIP relationships for transitions are recommended in lieu of the existing relationships contained in NCHRP Report 350. To facilitate the development of guidelines for the selection of a CIP for terminals, a new definition is proposed. The proposed definition for the CIP is the point along the terminal at which vehicle behavior transitions from gating to redirection. A methodology for determining the CIP using computer simulation techniques is investigated. The data clearly demonstrate that the selection of a single default impact location for all terminal configurations may not provide the CIP for many designs.

Drag Factors From Rollover Crash Testing for Crash Reconstructions

2011 ◽  
Author(s):  
Mark W. Arndt ◽  
Stephen M. Arndt ◽  
Donald Stevens
Keyword(s):  
Standard Deviation ◽  
Crash Testing ◽  
Naturally Occurring ◽  
Analysis Technique ◽  
Global Positioning ◽  
Original Works ◽  
Rollover Crash ◽  
Crash Tests ◽  
Gps Antenna ◽  
Drag Factor

A study of numerous published rollover tests was conducted by reexamination of the original works, analysis of their data, and centralized compilation of their results. Instances were identified where the original reported results for trip speed were in error, requiring revision because the analysis technique employed extrapolation versus integration and lacked correction for offset errors that develop by placing the Global Positioning System (GPS) antenna away from the vehicle Center of Gravity (CG). An analysis was performed demonstrating revised results. In total, 81 dolly rollover crash tests, 24 naturally occurring rollover crash tests, and 102 reconstructed rollovers were identified. Of the 24 naturally occurring tests, 18 were steer-induced rollover tests. Distributions of the rollover drag factors are presented. The range of drag factors for all examined dolly rollovers was 0.38 g to 0.50 g with the upper and lower 15 percent statistically trimmed. The average drag factor for dolly rollovers was 0.44 g (standard deviation = 0.064) with a reported minimum of 0.31 g and a reported maximum of 0.61 g. After revisions, the range of drag factors for the set of naturally occurring rollovers was 0.39 g to 0.50 g with the upper and lower 15 percent statistically trimmed. The average drag factor for naturally occurring rollovers was 0.44 g (standard deviation = 0.063) with a reported minimum of 0.33 g and a reported maximum of 0.57 g. These results provide a more probable range of the drag factor for use in accident reconstruction compared to the often repeated assertion that rollover drag factors range between 0.4 g and 0.65 g.

Development of a 34-in. Tall Thrie-Beam Guardrail Transition to Accommodate Future Roadway Overlays

2019 ◽  
Vol 2673 (2) ◽  
pp. 489-501
Author(s):  
Scott K. Rosenbaugh ◽  
Ronald K. Faller ◽  
Jennifer D. Schmidt ◽  
Robert W. Bielenberg
Keyword(s):  
Full Scale ◽  
Safety Performance ◽  
Performance Criteria ◽  
Concrete Barriers ◽  
Before And After ◽  
Level 3 ◽  
Crash Tests ◽  
Test Level

Roadway resurfacing and overlay projects effectively reduce the height of roadside barriers placed adjacent to the roadway, which can negatively affect their crashworthiness. More recently, bridge rails and concrete barriers have been installed with slightly increased heights to account for future overlays. However, adjacent guardrails and approach transitions have not yet been modified to account for overlays. The objective of this project was to develop an increased-height approach guardrail transition (AGT) to be crashworthy both before and after roadway overlays of up to 3 in. The 34-in. tall, thrie-beam transition detailed here was designed such that the system would be at its nominal 31-in. height following a 3-in. roadway overlay. Additionally, the upstream end of the AGT incorporated a symmetric W-to-thrie transition segment that would be replaced by an asymmetric transition segment after an overlay to keep the W-beam guardrail upstream from the transition at its nominal 31-in. height. The 34-in. tall AGT was connected to a modified version of the standardized buttress to mitigate the risk of vehicle snag below the rail. The barrier system was evaluated through two full-scale crash tests in accordance with Test Level 3 (TL-3) of AASHTO’s Manual for Assessing Safety Hardware (MASH) and satisfied all safety performance criteria. Thus, the 34-in. tall AGT with modified transition buttress was determined to be crashworthy to MASH TL-3 standards. Finally, implementation guidance was provided for the 34-in. tall AGT and its crashworthy variations.

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