Development of Metal-Cutting Guardrail Terminal

1996 ◽  
Vol 1528 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Brian G. Pfeifer ◽  
Dean L. Sicking
Keyword(s):  
Metal Cutting ◽  
Performance Standards ◽  
Full Scale ◽  
Dynamic Component ◽  
Roadside Safety ◽  
University Of Nebraska Lincoln ◽  
The University ◽  
The Impact ◽  
Crash Tests ◽  
Impact Head

A crashworthy terminal for strong-post W-beam guardrail systems was developed at the Midwest Roadside Safety Facility at the University of Nebraska—Lincoln. The terminal incorporates an impact head that is placed over the end of a tangent section of W-beam rail. The impact head is designed to be pushed down the rail and to dissipate impact energy by cutting the W-beam along the peaks and valley to produce four essentially flat strips of steel. These flat strips are then deflected out of the path of the vehicle, striking the end of the rail. Static and dynamic component tests as well as full-scale developmental crash tests conducted during the development of this system are described. Finally, the results of the three full-scale compliance crash tests are presented and discussed. The metal-cutting guardrail terminal was shown to meet NCHRP Report 230 safety performance standards.

New Energy-Absorbing High-Speed Safety Barrier

2003 ◽  
Vol 1851 (1) ◽  
pp. 53-64 ◽  
Author(s):  
John D. Reid ◽  
Ronald K. Faller ◽  
Jim C. Holloway ◽  
John R. Rohde ◽  
Dean L. Sicking
Keyword(s):  
High Speed ◽  
Steel Tube ◽  
Full Scale ◽  
Element Analysis ◽  
Dynamic Component ◽  
Testing Program ◽  
Roadside Safety ◽  
New Energy ◽  
University Of Nebraska Lincoln ◽  
Energy Absorbing

For many years, containment for errant racing vehicles traveling on oval speedways has been provided through rigid, concrete containment walls placed around the exterior of the track. However, accident experience has shown that serious injuries and fatalities may occur through vehicular impacts into these nondeformable barriers. Because of these injuries, the Indy Racing League and the Indianapolis Motor Speedway, later joined by the National Association for Stock Car Auto Racing (NASCAR), sponsored the development of a new barrier system by the Midwest Roadside Safety Facility at the University of Nebraska–Lincoln to improve the safety of drivers participating in automobile racing events. Several barrier prototypes were investigated and evaluated using both static and dynamic component testing, computer simulation modeling with LS-DYNA (a nonlinear finite element analysis code), and 20 full-scale vehicle crash tests. The full-scale crash testing program included bogie vehicles, small cars, and a full-size sedan, as well as Indy Racing League open-wheeled cars and NASCAR Winston Cup cars. A combination steel tube skin and foam energy-absorbing barrier system, referred to as the SAFER (steel and foam energy reduction) barrier, was successfully developed. Subsequently, the SAFER barrier was installed at the Indianapolis Motor Speedway in advance of the running of the 2002 Indianapolis 500 race. From the results of the laboratory testing program as well as analysis of the accidents into the SAFER barrier occurring during practice, qualification, and the race, the SAFER barrier has been shown to provide improved safety for drivers impacting the outer walls.

A Sub-System Test Methodology for Simulating EEVC Side Impact

2000 ◽  
Author(s):  
Krishnakanth Aekbote ◽  
Srinivasan Sundararajan ◽  
Joseph A. Prater ◽  
Joe E. Abramczyk
Keyword(s):  
Full Scale ◽  
Test Method ◽  
Side Impact ◽  
Vehicle Body ◽  
Crash Test ◽  
Vehicle Performance ◽  
Test Methodology ◽  
Supporting Frame ◽  
The Impact ◽  
Crash Tests

Abstract A sled based test method for simulating full-scale EEVC (European) side impact crash test is described in this paper. Both the dummy (Eurosid-1) and vehicle structural responses were simulated, and validated with the full-scale crash tests. The effect of various structural configurations such as foam filled structures, material changes, rocker and b-pillar reinforcements, advanced door design concepts, on vehicle performance can be evaluated using this methodology at the early stages of design. In this approach, an actual EEVC honeycomb barrier and a vehicle body-in-white with doors were used. The under-hood components (engine, transmission, radiator, etc.), tires, and the front/rear suspensions were not included in the vehicle assembly, but they were replaced by lumped masses (by adding weight) in the front and rear of the vehicle, to maintain the overall vehicle weight. The vehicle was mounted on the sled by means of a supporting frame at the front/rear suspension attachments, and was allowed to translate in the impact direction only. At the start of the simulation, an instrumented Eurosid-1 dummy was seated inside the vehicle, while maintaining the same h-point location, chest angle, and door-to-dummy lateral distance, as in a full-scale crash test. The EEVC honeycomb barrier was mounted on another sled, and care was taken to ensure that weight, and the relative impact location to the vehicle, was maintained the same as in full-scale crash test. The Barrier impacted the stationary vehicle at an initial velocity of approx. 30 mph. The MDB and the vehicle were allowed to slide for about 20 inches from contact, before they were brought to rest. Accelerometers were mounted on the door inner sheet metal and b-pillar, rocker, seat cross-members, seats, and non-struck side rocker. The Barrier was instrumented with six load cells to monitor the impact force at different sections, and an accelerometer for deceleration measurement. The dummy, vehicle, and the Barrier responses showed good correlation when compared to full-scale crash tests. The test methodology was also used in assessing the performance/crashworthiness of various sub-system designs of the side structure (A-pillar, B-pillar, door, rocker, seat cross-members, etc.) of a passenger car. This paper concerns itself with the development and validation of the test methodology only, as the study of various side structure designs and evaluations are beyond the scope of this paper.

The Reconstruction Scheme Design and Experiment of the Height-Adjustable W-Beam Guardrail

2012 ◽  
Vol 490-495 ◽  
pp. 2676-2680
Author(s):  
Hong Jun Cui ◽  
Xiao Jing Shen ◽  
Yu Liu ◽  
Xi Xin Sun
Keyword(s):  
Computer Simulation ◽  
Full Scale ◽  
Scheme Design ◽  
Roadside Safety ◽  
Reconstruction Scheme ◽  
Crash Tests

Pave overlay to the freeway repeatedly causes the guardrail’s height lower and lower, which seriously influences its performance in protection and safety. The paper aims to work out a height-adjustable W-beam guardrail which is economic, feasible and safe to solve the shortage in barrier’s height causes from paving overlays by computer simulation tests and full-scale crash tests, which will improve the roadside safety of the guardrail and save the reconstruction cost.

Effect of Light Poles on Vehicle Impacts with Roadside Barriers

1997 ◽  
Vol 1599 (1) ◽  
pp. 32-39 ◽  
Author(s):  
James C. Kennedy
Keyword(s):  
Full Scale ◽  
Lack Of Information ◽  
Large Numbers ◽  
Highway Network ◽  
Accident Data ◽  
Full Scale Tests ◽  
Light Pole ◽  
National Cooperative ◽  
The Impact ◽  
Crash Tests

Light poles installed within the deflection zone of roadside barriers (guardrails) may influence the ability of the guardrail to safely redirect an impacting vehicle. One concern is that, during an impact, the vehicle may pivot about the relatively rigid light pole and then spin away from the guardrail back into the traffic stream in an uncontrolled, unsafe manner. A large percentage of the highway network in Ohio uses the type of guardrail and light pole configurations, in which the breakaway light poles are placed at either 15.2- or 45.7-cm (6- or 18-in.) lateral distance from the back of the guardrail, depending on one of two light pole base designs in use. These pole-guardrail systems were placed in large numbers some years ago and Ohio accident data have been inadequate to provide information to determine whether or not a problem exists with this system. Proposed highway rehabilitation and reconstruction projects can include changes or adjustments to placement of guardrails and light poles, but there was a lack of information as to whether or not the past practices possessed a problem. A study was conducted to determine if light poles have an adverse effect on the redirecting performance of guardrails. It included six full-scale crash tests involving two vehicle weight classes (2000P and 820C), two light pole base designs (AT-A and AT-X), and a typical guardrail used in Ohio [Type 5 (W-Beam)]. All full-scale tests were carried out according to the recommended procedures in National Cooperative Highway Research Program (NCHRP) Report 350. The actual vehicles used for the 2000P class were half-ton pickup trucks ballasted to simulate the weight and mass characteristics of the 2000P vehicle that is specified in NCHRP Report 350. The guardrail–light pole system was not shown to cause snagging or subsequent unstable motion of the vehicle due to impact. All vehicles exited the guardrail in a stable manner. No change in the arrangement of light poles behind the Type 5 guardrail is contemplated. The redirecting function of the guardrail was not compromised as a result of placement of the light pole behind the length-of-need. Excessive exit angle situations (according to NCHRP Report 350) occurred in three tests involving the simulated 2000P class vehicles. However, the impact conditions employed for these tests were extreme, and the likelihood of this situation occurring under everyday highway usage may be small.

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.

scholarly journals Impact Performance Evaluation of a Crash Cushion Design Using Finite Element Simulation and Full-Scale Crash Testing

Safety ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 48
Author(s):  
Murat Büyük ◽  
Ali Atahan ◽  
Kenan Kurucuoğlu
Keyword(s):  
Finite Element ◽  
Performance Evaluation ◽  
Element Model ◽  
Full Scale ◽  
Plastic Energy ◽  
Impact Performance ◽  
Steel Cables ◽  
Energy Absorbing ◽  
The Impact ◽  
Crash Tests

Crash cushions are designed to gradually absorb the kinetic energy of an impacting vehicle and bring it to a controlled stop within an acceptable distance while maintaining a limited amount of deceleration on the occupants. These cushions are used to protect errant vehicles from hitting rigid objects, such as poles and barriers located at exit locations on roads. Impact performance evaluation of crash cushions are attained according to an EN 1317-3 standard based on various speed limits and impact angles. Crash cushions can be designed to absorb the energy of an impacting vehicle by using different material deformation mechanisms, such as metal plasticity supported by airbag folding or damping. In this study, a new crash cushion system, called the ulukur crash cushion (UCC), is developed by using linear, low-density polyethylene (LLDPE) containers supported by embedded plastic energy-absorbing tubes as dampers. Steel cables are used to provide anchorage to the design. The crashworthiness of the system was evaluated both numerically and experimentally. The finite element model of the design was developed and solved using LS-DYNA (971, LSTC, Livermore, CA, USA), in which the impact performance was evaluated considering the EN 1317 standard. Following the simulations, full-scale crash tests were performed to determine the performance of the design in containing and redirecting the impacting vehicle. Both the simulations and crash tests showed acceptable agreement. Further crash tests are planned to fully evaluate the crashworthiness of the new crash cushion system.

Performance of Breakaway Cable and Modified Eccentric Loader Terminals in Iowa and North Carolina: In-Service Evaluation

2000 ◽  
Vol 1720 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Malcolm H. Ray ◽  
Jeffery A. Hopp
Keyword(s):  
North Carolina ◽  
Performance Evaluation ◽  
Service Evaluation ◽  
Full Scale ◽  
Service Performance ◽  
Roadside Safety ◽  
Occupant Injuries ◽  
Crash Tests

Developing safe and effective guardrail terminals has been a high priority for roadside safety researchers for several decades. Numerous full-scale crash tests have been performed, and many new types of terminals have been developed. Results are presented of an in-service performance evaluation of two popular guardrail terminals—the breakaway cable terminal and the modified eccentric loader terminal. The data were collected in parts of Iowa and North Carolina during a 24-month period from 1997 to 1999. The collision characteristics, occupant injuries, and barrier damage were evaluated to determine collision performance.

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.

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