Investigation and MASH Full-Scale Crash Testing of the Practice of Raising Blockouts on W-Beam Rail Systems

2022 ◽  
pp. 036119812110654
Author(s):  
Chiara Silvestri Dobrovolny ◽  
Roger Bligh ◽  
Maysam Kiani ◽  
Ali Hangul
Keyword(s):  
Barrier Height ◽  
Research Study ◽  
Full Scale ◽  
Crash Test ◽  
Crash Testing ◽  
Rail Systems ◽  
Federal Highway

The Federal Highway Administration (FHWA) clarifies appropriate height measures for W-beam guardrails. Identification of existing locations where rail height is lower than recommended by FHWA is common. A research study was conducted to investigate the crashworthiness of raising blockouts on posts to restore barrier height and provide clarification on implementation of such methodology. The researchers evaluated the crashworthiness of raising blockouts by conducting a full-scale Manual for Assessing Safety Hardware (MASH) Crash Test 3-11 of a 28-in. W-beam guardrail system with composite blockouts raised 4 in. on posts. The 28-in. W-beam guardrail system with raised composite blockouts contained and redirected the 2270P vehicle, and it performed acceptably for MASH Test 3-11. The results of this study include guidance on the procedure for raising blockout mounting height on steel posts to achieve recommended rail height for a W-beam guardrail.

Finite Element Simulation of a Strong-Post W-Beam Guardrail System

SIMULATION ◽  
2002 ◽  
Vol 78 (10) ◽  
pp. 587-599 ◽  
Author(s):  
Ali O. Atahan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Full Scale ◽  
Nonlinear Finite Element ◽  
Crash Test ◽  
Original Design ◽  
Dynamic Interactions ◽  
Crash Testing ◽  
Element Simulation ◽  
Test Requirements

Computer simulation of vehicle collisions has improved significantly over the past decade. With advances in computer technology, nonlinear finite element codes, and material models, full-scale simulation of such complex dynamic interactions is becoming ever more possible. In this study, an explicit three-dimensional nonlinear finite element code, LS-DYNA, is used to demonstrate the capabilities of computer simulations to supplement full-scale crash testing. After a failed crash test on a strong-post guardrail system, LS-DYNA is used to simulate the system, determine the potential problems with the design, and develop an improved system that has the potential to satisfy current crash test requirements. After accurately simulating the response behavior of the full-scale crash test, a second simulation study is performed on the system with improved details. Simulation results indicate that the system performs much better compared to the original design.

Development of a 100-km/h Reusable High-Molecular Weight/High-Density Polyethylene Truck-Mounted Attenuator

1998 ◽  
Vol 1647 (1) ◽  
pp. 75-88
Author(s):  
John F. Carney ◽  
Subhasish Chatterjee ◽  
Richard B. Albin
Keyword(s):  
Molecular Weight ◽  
Kinetic Energy ◽  
High Molecular Weight ◽  
High Density Polyethylene ◽  
Full Scale ◽  
High Density ◽  
Crash Test ◽  
Crash Testing ◽  
Impact Attenuation ◽  
Risk Parameters

A reusable truck-mounted attenuator has been developed that dissipates kinetic energy through the lateral deformation of a nested cluster of high-molecular weight/high-density polyethylene cylinders. This 100-km/h impact attenuation device, called the Vanderbilt truck-mounted attenuator (VTMA), satisfies the crash testing requirements of NCHRP Report 350. It has been approved by the Federal Highway Administration for use on the national highway system under these NCHRP Report 350 guidelines. Most impact attenuation devices currently employed require the replacement of damaged structural components and spent-energy-dissipating elements following an impact event. Until these repairs and refurbishments are carried out, these safety devices are largely ineffective because they are unable to dissipate kinetic energy in a subsequent impact in an acceptable manner such that relevant occupant risk parameters are within prescribed limits. The VTMA is a reusable and self-restorative truck-mounted attenuator. It can dissipate large amounts of kinetic energy, undergo significant deformations and strains without fracturing, and then, essentially, regain its original shape and energy-dissipation potential on removal of the load. The VTMA design was optimized through finite-element modeling using DYNA3D. This inexpensive modeling tool resulted in a reduction in the number of expensive full-scale crash tests required to develop the system. Computer modeling can optimize the probability for success of a given full-scale crash test, removing the trial-and-error approach to appurtenance design.

Minimum Effective Length for the Midwest Guardrail System

2015 ◽  
Vol 2521 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Jennifer D. Schmidt ◽  
John D. Reid ◽  
Nicholas A. Weiland ◽  
Ronald K. Faller
Keyword(s):  
System Performance ◽  
Evaluation Criteria ◽  
Full Scale ◽  
Effective Length ◽  
Crash Test ◽  
Minimum Length ◽  
Test Results ◽  
Crash Testing ◽  
Level 3 ◽  
System Length

The recommended minimum length for the standard Midwest Guardrail System (MGS) is 175 ft (55.3 m) based on crash testing according to NCHRP Report 350 and AASHTO's Manual for Assessing Safety Hardware (MASH) specifications. However, varying roadside hazards and roadway geometries may require a W-beam guardrail system to be shorter than the currently tested minimum length. The effects of reducing system length for the MGS were therefore investigated. The research study included one full-scale crash test with a Dodge Ram pickup truck striking a 75-ft (22.9-m) long MGS system. The barrier system satisfied all MASH Test Level 3 (TL-3) evaluation criteria for Test Designation Number 3-11. Test results confirmed that the reduced system length did not adversely affect overall system performance or deflections. Simulations that used BARRIER VII and LS-DYNA were also conducted to analyze system performance with reduced lengths of 50 ft (15.2 m) and 62 ft 6 in. (19.1 m). Both system lengths exhibited the potential for successfully redirecting an errant vehicle at MASH TL-3 test conditions. However, these reduced-length systems would have a narrow window for redirecting vehicles and would be able to shield hazards of only a limited size. Owing to limitations associated with the computer simulations, full-scale crash testing is recommended before these shorter systems are installed.

Development of a New Manual for Assessing Safety Hardware TL-3 Low-Profile Portable Concrete Barrier for High-Speed Applications

2019 ◽  
Vol 2673 (7) ◽  
pp. 630-640
Author(s):  
Chiara Silvestri Dobrovolny ◽  
Shengyi Shi ◽  
James Kovar ◽  
Roger P. Bligh ◽  
Stefan Hurlebaus
Keyword(s):  
High Speed ◽  
Evaluation Criteria ◽  
Full Scale ◽  
Crash Testing ◽  
Sight Distance ◽  
Low Profile ◽  
Rail Systems ◽  
Distance Problem ◽  
Crash Tests ◽  
Concrete Barrier

A sight-distance problem is associated with use of 32-in. tall concrete longitudinal barriers, specifically in certain work zone locations and at nighttime. These 32-in. tall barriers can obstruct drivers’ eyesight, making it difficult for drivers to detect oncoming vehicles on the other side of these barriers. To address this sight-distance problem while protecting the errant vehicles, researchers at the Texas Transportation Institute (TTI) developed a 20-in. tall low-profile portable concrete barrier (PCB) for use in low-speed work zones in the early 1990s. To address the problem for high-speed application, TTI researchers applied modifications to the 20-in. tall low-profile PCB. Researchers designed two retrofit metal rail systems to be added on top of the existing 20-in. tall low-profile PCB to address roadside and median applications. The systems successfully performed in full-scale crash testing according to NCHRP Report 350 Test Level (TL) 3 evaluation criteria. This paper describes the efforts to develop and evaluate the crashworthiness of a new low-profile PCB design for high-speed applications. The crash tests were performed following Manual for Assessing Safety Hardware (MASH) guidelines and evaluation criteria. Based on results from finite element computer simulations performed to aid design, MASH full-scale crash tests were conducted on a low-profile PCB system comprised of 26-in. tall, 30-ft long barrier segments, with a T-shaped profile. Based on constructability feedback, the sides of the barrier were formed with a negative 1:18 slope, which allows for ease of construction forming. The new low-profile PCB performed acceptably as a MASH TL-3 longitudinal barrier.

Long-Span Guardrail System for Culvert Applications

2000 ◽  
Vol 1720 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Ronald K. Faller ◽  
Dean L. Sicking ◽  
Karla A. Polivka ◽  
John R. Rohde ◽  
Bob W. Bielenberg
Keyword(s):  
Simulation Modeling ◽  
Research Study ◽  
Full Scale ◽  
Wood Block ◽  
Long Span ◽  
Crash Testing ◽  
Vehicle Crash ◽  
Level 3 ◽  
Crash Tests ◽  
Test Level

A long-span guardrail for use over low-fill culverts was developed and successfully crash tested. The guardrail system was configured with 30.48 m of nested, 12-gauge W-beam rail and centered around a 7.62-m-long unsupported span. The nested W-beam rail was supported by 16 W152×13.4 steel posts and 6 standard CRT posts, each with two 150-mm×200×360 mm wood block-outs. Each post was 1830 mm long. Post spacings were 1905 mm on center, except for the 7.62-m spacing between the two CRT posts surrounding the long span. The research study included computer simulation modeling with Barrier VII and full-scale vehicle crash testing, using 3/4-ton (680-kg) pickup trucks in accordance with the Test Level 3 (TL-3) requirements specified in NCHRP Report 350. Three full-scale vehicle crash tests were performed. The first test was unsuccessful because of severe vehicle penetration into the guardrail system. This penetration resulted from a loss of rail tensile capacity during vehicle redirection when the swagged fitting on the cable anchor assembly failed. A second test was performed on the same design, which contained a new cable anchor assembly. During vehicle redirection, the pickup truck rolled over and the test was considered a failure. The long-span system was subsequently redesigned to incorporate double block-outs on the CRT posts and crash tested again. Following the successful third test, the long-span guardrail system was determined to meet TL-3 criteria.

Full-Scale Crash Testing Facilities for a Railway Vehicle

2012 ◽  
Author(s):  
Jin Sung Kim ◽  
Hyun Seung Jung ◽  
Tae Soo Kwon ◽  
Won Mok Choi ◽  
Seung Wan Son
Keyword(s):  
High Speed ◽  
Impact Test ◽  
Full Scale ◽  
Displacement Sensor ◽  
Crash Test ◽  
Railway Vehicle ◽  
Single Item ◽  
Railway Vehicles ◽  
Crash Testing ◽  
The Impact

KRRI (Korea Railroad Research Institute) has successfully performed several tens of impact tests of crash parts for a railway vehicles. Full-scale crash testing facilities were newly established including a crash barrier, dynamic load cell, high speed DAS (Data Acquisition System), a laser displacement sensor, dummies, a motor car and etc. This paper introduces series of impact test results using full-scale crash testing facilities. The impact test for railway vehicles consists of three categories, i.e. single item tests, module tests and crash structure tests. For single item tests, expansion tubes, composite tubes, collapsible tubes and etc. were tested. For module tests, a crash test of a light collision safety device with an expansion tube and triggering mechanism was performed. For crash structure tests, several full-scale crash tests were performed including front-end and cab structures with or without dummies. The crash testing equipment developed will be able to evaluate the occupant safety as well as the structural crashworthiness of a train.

Finite-Element Model of Modified Eccentric Loader Terminal (MELT)

1997 ◽  
Vol 1599 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Malcolm H. Ray ◽  
Gregory S. Patzner
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Full Scale ◽  
Crash Test ◽  
Finite Element Software ◽  
Passenger Vehicles ◽  
The Past ◽  
Crash Testing ◽  
Nonlinear Finite Element Model

Improving the performance of guardrail terminals and end treatments in impacts with passenger vehicles has been an active area of research over the past decade. One particular W-beam guardrail terminal that has been the focus of recent full-scale crash testing is the Modified Eccentric Loader Terminal (MELT). The development of a nonlinear, finite-element model of a recent modification of the MELT is being used to learn more about the performance of this type of guardrail terminal. A finite-element model of the MELT was developed using the TrueGrid preprocessor and the LS-DYNA3D finite-element software was used to perform the analysis. Results of the analysis are compared with data from a full-scale crash test involving a small passenger car.

Numerical Investigation of the Performance of a Roadside Safety Barrier Located Behind the Break Point of a Slope

2011 ◽  
Author(s):  
M. Mongiardini ◽  
J. D. Reid
Keyword(s):  
Numerical Investigation ◽  
Experimental Tests ◽  
Break Point ◽  
Full Scale ◽  
Crash Test ◽  
Construction Costs ◽  
Roadside Safety ◽  
The Road ◽  
Safety Barrier ◽  
Mechanically Stabilized

Numerical simulations allow engineers in roadside safety to investigate the safety of retrofit designs minimizing or, in some cases, avoiding the high costs related to the execution of full-scale experimental tests. This paper describes the numerical investigation made to assess the performance of a roadside safety barrier when relocated behind the break point of a 3H:1V slope, found on a Mechanically Stabilized Earth (MSE) system. A safe barrier relocation in the slope would allow reducing the installation width of the MSE system by an equivalent amount, thus decreasing the overall construction costs. The dynamics of a pick-up truck impacting the relocated barrier and the system deformation were simulated in detail using the explicit non-linear dynamic finite element code LS-DYNA. The model was initially calibrated and subsequently validated against results from a previous full-scale crash test with the barrier placed at the slope break point. After a sensitivity analysis regarding the role of suspension failure and tire deflation on the vehicle stability, the system performance was assessed when it was relocated into the slope. Two different configurations were considered, differing for the height of the rail respect to the road surface and the corresponding post embedment into the soil. Conclusions and recommendations were drawn based on the results obtained from the numerical analysis.

Design and Full-Scale Testing of M50/P1 Bolt-Down Removeable Bollard System

2018 ◽  
Vol 2672 (41) ◽  
pp. 24-33
Author(s):  
William F. Williams
Keyword(s):  
Urban Areas ◽  
Full Scale ◽  
Shallow Foundations ◽  
Test Installation ◽  
Additional Information ◽  
Performance Requirements ◽  
Crash Testing ◽  
Design And Testing ◽  
Base Plates ◽  
Full Scale Testing

The purpose of this project was to design and test a new bolt-down bollard system that meets the requirements of American Standards for Testing Materials (ASTM) Designation F2656-15 M50/P1 impact conditions. The test installation consisted of three vertical 10-in. diameter (nominal) bollards with welded base plates bolted to a shallow reinforced concrete foundation. The foundation for this system was sized to reduce the foundation embedment. Shallow foundations are often necessary for use in cities and urban areas where utilities can conflict with deeper foundations. Standard common members and materials were used in the installation to accommodate fabrication and installation in locations all over the world. The bollards can be removed to provide access if necessary. Full-scale testing was performed on the bolt-down bollard system. The bollard system design for this project successfully met the requirements of M50/P1 with a total payload penetration of less than 1 m. The new bollard design successfully met all the performance requirements for ASTM F2656-15 M50/P1. Details of the design and testing of the bolt-down bollard system are provided in this paper. Crash-testing videos and additional information on the design and full-scale testing will be provided in the presentation.

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