A Base Study to Investigate MASH Conservativeness of Occupant Risk Evaluation

2016 ◽  
Author(s):  
Chiara Silvestri Dobrovolny ◽  
Harika Reddy Prodduturu ◽  
Dusty R. Arrington ◽  
Nathan Schulz ◽  
Stefan Hurlebaus ◽  
...  
Keyword(s):  
Risk Evaluation ◽  
Injury Risk ◽  
Evaluation Criteria ◽  
Oblique Impact ◽  
Full Scale ◽  
Crash Test ◽  
Vehicle Interior ◽  
Impact Performance ◽  
Space Model ◽  
The Impact

The Manual for Assessing Safety Hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation. A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the Flail Space Model in a full scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event. Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.

A Base Study to Investigate MASH Conservativeness of Occupant Risk Evaluation

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Nathan Schulz ◽  
Chiara Silvestri Dobrovolny ◽  
Stefan Hurlebaus ◽  
Harika Reddy Prodduturu ◽  
Dusty R. Arrington ◽  
...  
Keyword(s):  
Risk Evaluation ◽  
Injury Risk ◽  
Evaluation Criteria ◽  
Oblique Impact ◽  
Full Scale ◽  
Crash Test ◽  
Fe Model ◽  
Vehicle Interior ◽  
Space Model ◽  
The Impact

Abstract The manual for assessing safety hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation. A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the flail space model (FSM) in a full-scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event. Additionally, a finite element (FE) model was developed and calibrated against the full-scale crash test. The calibrated model can be used to perform parametric simulations with different testing conditions. Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.

Impact Performance of the G4(1W) and G4(2W) Guardrail Systems: Comparison Under NCHRP Report 350 Test 3-11 Conditions

2000 ◽  
Vol 1720 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Chuck A. Plaxico ◽  
Malcolm H. Ray ◽  
Kamarajugadda Hiranmayee
Keyword(s):  
The United States ◽  
Full Scale ◽  
Nonlinear Finite Element ◽  
Crash Test ◽  
Test Vehicle ◽  
Element Analysis ◽  
Impact Performance ◽  
Performance Requirements ◽  
The Impact ◽  
Standard Techniques

Several types of strong-post W-beam guardrails are used in the United States. Usually the only difference between one type of strong-post W-beam guardrail and another is the choice of post and block-out types. The impact performance of two very similar strong-post W-beam guardrails are compared—the G4(2W), which uses a 150×200 mm wood post and the G4(1W), which uses a 200×200 mm wood post. Although G4(2W) is used in numerous states, G4(1W) is now common only in the state of Iowa. The performance of the two guardrails has been presumed equal, but only one full-scale crash test has been performed on G4(1W) and that was over 30 years ago, using a now-obsolete test vehicle. The nonlinear finite element analysis program LS-DYNA was used to evaluate the crashworthiness of the two guardrails. The G4(2W) guardrail model was validated with the results of a full-scale crash test. A model of the G4(1W) guardrail system was developed, and the deflection, vehicle redirection, and occupant risk factors of the two guardrails were compared. The impact performance of the two guardrails was quantitatively compared using standard techniques. The analysis results indicate similar collision performance for G4(1W) and G4(2W) and show that both satisfy NCHRP Report 350 Test 3-11 safety performance requirements.

Flared Energy-Absorbing Terminal Median Barrier

2002 ◽  
Vol 1797 (1) ◽  
pp. 89-95
Author(s):  
John R. Rohde ◽  
John D. Reid ◽  
Dean L. Sicking
Keyword(s):  
Evaluation Criteria ◽  
Reverse Direction ◽  
Crash Test ◽  
Impact Performance ◽  
Pickup Truck ◽  
Terminal Set ◽  
Level 3 ◽  
Energy Absorbing ◽  
The Impact ◽  
Crash Tests

The design and crash test results of a median barrier version of the Flared Energy-Absorbing Terminal, known as FLEAT-MT, are presented. This energy-absorbing terminal is designed for use with a W-beam, strong-post median barrier. The FLEAT-MT terminal uses two standard FLEAT terminals, one for each of the two W-beam rail elements. The energy-absorbing capability of the FLEAT-MT terminal is based on the sequential kinking concept, similar to that used with the Sequential Kinking Terminal and FLEAT guardrail terminals. Three full-scale vehicle crash tests were conducted to evaluate the impact performance of the FLEAT-MT terminal in accordance with guidelines set forth in NCHRP Report 350: Test 3-35—pickup truck redirection test (Test No. FMT-1), Test 3-31—pickup truck head-on test (Test No. FMT-2), and Test 3-39—pickup truck reverse-direction test (Test No. FMT-3M). The terminal performed as designed. The FLEAT-MT terminal meets all evaluation criteria for a Test Level 3 median barrier terminal set forth in NCHRP Report 350. The FLEAT-MT terminal is being evaluated by FHWA for approval to be used on the National Highway System.

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.

Repeated Impacts Diminish the Impact Performance of Equestrian Helmets

2019 ◽  
Vol 28 (4) ◽  
pp. 368-372
Author(s):  
Carl G. Mattacola ◽  
Carolina Quintana ◽  
Jed Crots ◽  
Kimberly I. Tumlin ◽  
Stephanie Bonin
Keyword(s):  
Injury Risk ◽  
Head Injuries ◽  
The United States ◽  
Expanded Polystyrene ◽  
Head Acceleration ◽  
Safety Equipment ◽  
Impact Performance ◽  
Computed Tomography Scans ◽  
Impact Attenuation ◽  
The Impact

Context: During thoroughbred races, jockeys are placed in potentially injurious situations, often with inadequate safety equipment. Jockeys frequently sustain head injuries; therefore, it is important that they wear appropriately certified helmets. Objective: The goals of this study are (1) to perform impact attenuation testing according to ASTM F1163-15 on a sample of equestrian helmets commonly used by jockeys in the United States and (2) to quantify headform acceleration and residual crush after repeat impacts at the same location. Participants and Design: Seven helmet models underwent impact attenuation testing according to ASTM F1163-15. A second sample of each helmet model underwent repeat impacts at the crown location for a total of 4 impacts. Setting: Laboratory. Intervention: Each helmet was impacted against a flat and equestrian hazard anvil. Main Outcome Measures: Headform acceleration was recorded during all impact and computed tomography scans were performed preimpact and after impacts 1 and 4 on the crown to quantify liner thickness. Results: Four helmets had 1 impact that exceeded the limit of 300g. During the repeated crown impacts, acceleration remained below 300g for the first and second impacts for all helmets, while only one helmet remained below 300g for all impacts. Foam liner thickness was reduced between 5% and 39% after the first crown impact and between 33% and 70% after the fourth crown impact. Conclusions: All riders should wear a certified helmet and replace it after sustaining a head impact. Following an impact, expanded polystyrene liners compress, and their ability to attenuate head acceleration during subsequent impacts to the same location is reduced. Replacing an impacted helmet may reduce a rider’s head injury risk.

Crash Testing and Evaluation of Work Zone Traffic Control Devices

1998 ◽  
Vol 1650 (1) ◽  
pp. 45-54 ◽  
Author(s):  
King K. Mak ◽  
Roger P. Bligh ◽  
Lewis R. Rhodes
Keyword(s):  
Traffic Control ◽  
Evaluation Criteria ◽  
Work Zone ◽  
Work Zones ◽  
Impact Performance ◽  
Crash Testing ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Under Construction ◽  
The Impact

Safety of work zones is a major area of concern since it is not always possible to maintain a level of safety comparable to that of a normal highway not under construction. Proper traffic control is critical to the safety of work zones. However, traffic control devices themselves may pose a safety hazard when impacted by errant vehicles. The impact performance of many work zone traffic control devices is mostly unknown, and little, if any, crash testing has been conducted in accordance with guidelines set forth in NCHRP Report 350. The Texas Department of Transportation (TxDOT) has, in recent years, sponsored a number of studies at the Texas Transportation Institute to assess the impact performance of various work zone traffic control devices, including plastic drums and sign substrates, temporary and portable sign supports, plastic cones, vertical panels, and barricades. The results, findings, conclusions, and recommendations are presented for temporary and portable sign supports, plastic drums, sign substrates for use with plastic drums, traffic cones, and vertical panels, whereas those for barricades are covered elsewhere. Most of the work zone traffic control devices satisfactorily met the evaluation criteria set forth in NCHRP Report 350 and are recommended for field implementation. However, some of the devices failed to perform satisfactorily and are not recommended for field applications. The results from these studies are being incorporated into the TxDOT barricade and construction standard sheets for use in work zones.

scholarly journals Impact Analysis of Transition between Semi-Rigid and Rigid Barriers Using Simulations

2021 ◽  
Vol 21 (6) ◽  
pp. 9-19
Author(s):  
Kyoungju Kim ◽  
Hyunung Bae ◽  
Jongmin Kim
Keyword(s):  
Impact Analysis ◽  
Transition System ◽  
Full Scale ◽  
Impact Behavior ◽  
Crash Test ◽  
Special Design ◽  
Collision Safety ◽  
Stable Performance ◽  
Impact Simulations ◽  
The Impact

Transition is a type of barrier that connects other barriers with different grades and shapes. Even if each barrier satisfies the performance, it may not be satisfied in transition. Therefore, collision safety requires a special design and examination. In this study, we investigated national and foreign standards and situations for the proper configuration of the transition and analyzed the impact behavior of the general transition using impact simulations. We developed a transition system that could ensure the stable performance of various grades by analyzing the behavior and confirmed based on the full-scale crash test (SB2 level).

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.

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.

Box-Beam Burster Energy-Absorbing Single-Sided Crash Cushion

2002 ◽  
Vol 1797 (1) ◽  
pp. 72-81
Author(s):  
John D. Reid ◽  
John R. Rohde ◽  
Dean L. Sicking
Keyword(s):  
Evaluation Criteria ◽  
Reverse Direction ◽  
Impact Performance ◽  
Pickup Truck ◽  
Barrier Energy ◽  
Box Beam ◽  
Level 3 ◽  
Energy Absorbing ◽  
The Impact ◽  
Crash Tests

A new box-beam burster energy-absorbing single-sided crash cushion (BEAT-SSCC) was designed and crash tested. This energy-absorbing crash cushion is designed to shield a rigid hazard, such as the end of a concrete safety-shaped barrier. Energy-absorbing capabilities of the BEAT-SSCC are based on the bursting tube technology, similar to that used with the box-beam burster energy-absorbing terminal. Five full-scale vehicle crash tests were conducted to evaluate the impact performance of the BEAT-SSCC in accordance with guidelines set forth in NCHRP Report 350: ( a) Test Designation 3-31—pickup truck head-on test; ( b) Test Designation 3-38—pickup truck critical impact point test (two tests to evaluate two different critical impact points); ( c) Test Designation 3-39—pickup truck reverse direction test at midpoint of crash cushion, and ( d) modified Test Designation 3-39—pickup truck reverse direction test at connection to the concrete barrier. The crash cushion performed as designed, and the BEAT-SSCC meets all evaluation criteria for a Test Level 3 crash cushion set forth in NCHRP Report 350. The BEAT-SSCC is being evaluated by FHWA for approval to be used on the National Highway System.

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