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.

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.

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.

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.

Low-velocity impact properties and finite element analysis of syntactic foam reinforced by warp-knitted spacer fabric

2016 ◽  
Vol 87 (16) ◽  
pp. 1938-1952 ◽  
Author(s):  
Chao Zhi ◽  
Hairu Long ◽  
Fengxin Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Syntactic Foam ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Impact Performance ◽  
Spacer Fabric ◽  
The Impact

The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted spacer fabric (SF-WKSF). In order to discuss the effect of warp-knitted spacer fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were fabricated, including different WKSF surface layer structures, different spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a finite element analysis finished with ANSYS/LS-DYNA and LS-PrePost was used to simulate the impact behaviors of SF-WKSF. The results of the finite element analysis are in agreement with the experimental results.

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.

Design of the SAFER Emergency Gate Using LS-DYNA

2005 ◽  
Author(s):  
Robert W. Bielenberg ◽  
John D. Rohde ◽  
John D. Reid
Keyword(s):  
Impact Load ◽  
High Strength ◽  
Full Scale ◽  
Element Analysis ◽  
Worst Case ◽  
Crash Testing ◽  
Additional Protection ◽  
Energy Absorbing ◽  
The Impact ◽  
Gate Design

In recent years, NASCAR and the Indy Racing League have improved the safety of their racetracks through the installation of the Steel And Foam Energy Reduction barrier (SAFER). The new barrier consists of a high-strength, tubular steel skin that distributes the impact load to energy-absorbing foam cartridges in order to reduce the severity of the impact, extends the impact event, and provides the occupant of the race car additional protection. During installation of the SAFER barrier, the designers realized that certain race tracks were designed with the emergency track exit in the outside of the corner. Because the SAFER barrier needed to be installed in these corners, a gate mechanism had to be designed for the barrier that would provide access to the track while retaining the safety performance of the system. Full-scale crash testing of the first SAFER gate design showed that the gate did not posses sufficient capacity to handle the loads experienced during a worst-case impact scenario. Non-linear finite element analysis was then used to redesign the gate mechanism. The original gate design was simulated using LS-DYNA in order to validate the computational model. Modifications to increase the capacity of the gate mechanism were designed and analyzed until suitable results were obtained through simulation. Finally, the redesigned SAFER gate was successfully full-scale crash tested.

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.

scholarly journals Repeatability of Full-Scale Crash Tests and Criteria for Validating Simulation Results

1996 ◽  
Vol 1528 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Malcolm H. Ray
Keyword(s):  
Finite Element ◽  
Full Scale ◽  
Crash Test ◽  
Test Results ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Simulation Results ◽  
Crash Tests

A method of comparing two acceleration time histories to determine whether they describe similar physical events is described. The method can be used to assess the repeatability of full-scale crash tests and it can also be used as a criterion for assessing how well a finite-element analysis of a collision event simulates a corresponding full-scale crash test. The method is used to compare a series of six identical crash tests and then is used to compare several finite-element analyses with full-scale crash test results.

Test Level 4 Bridge Rails

2000 ◽  
Vol 1720 (1) ◽  
pp. 80-94
Author(s):  
C. Eugene Buth ◽  
Wanda L. Menges ◽  
William F. Williams
Keyword(s):  
Full Scale ◽  
Safety Performance ◽  
Crash Test ◽  
Test Results ◽  
Recent Past ◽  
Design Specifications ◽  
Performance Requirements ◽  
Steel Tubing ◽  
Aashto Lrfd ◽  
Test Level

Design details and full-scale crash test results are presented for three bridge rails tested for compliance with NCHRP Report 350 Test Level 4 requirements. Designs of these rails are based on AASHTO LRFD Bridge Design Specifications. Each bridge rail consists of structural steel tubing rail elements mounted on wide-flange posts. The rails are generally stronger than many designs commonly used in the recent past. Full-scale crash test results demonstrated that all bridge rails meet NCHRP Report 350 safety performance requirements.

Analysis of the Impact of Concrete Compressive Strength Reduction in Joint Core Area on Super High-Rise Structures

2013 ◽  
Vol 438-439 ◽  
pp. 690-695
Author(s):  
Xiao Yu ◽  
Na Wu ◽  
Zhao Yang ◽  
Kai Xu
Keyword(s):  
Compressive Strength ◽  
Cross Sections ◽  
Concrete Strength ◽  
Nonlinear Finite Element ◽  
Core Area ◽  
Concrete Compressive Strength ◽  
Element Analysis ◽  
High Rise ◽  
The Impact ◽  
Joint Core Area

t is focused on a super high-rise building structure, of which the concrete compressive strength is reduced in joint core. The whole structure is calculated with program SATWE. Based on this calculation, integral stress analysis by MIDAS when concrete strength is reduced in joint core area and nonlinear finite element analysis by ANSYS on the joints of the worst cross-sections in the whole structure are developed. Thus the adverse effect of reduced concrete strength in joint core area on super high-rise structures is found out.

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