Development of the Midwest Guardrail System

A revised guardrail system has been developed that should provide greatly improved performance for high-center-of-gravity light truck vehicles. The barrier incorporates W-beam guardrail and standard W6×9 steel posts. Primary changes to the design include raising the standard rail height to 635 mm, moving rail splices to midspan between posts, increasing blockout size, and increasing the size of post bolt slots. All of these changes were designed to improve the barrier’s performance with high-center-of-gravity vehicles. One full-scale crash test was conducted to verify that the guardrail would perform adequately with mini-sized automobiles when raised to 660 mm to the center of the rail. This test proved that the barrier can provide satisfactory performance when mounted at heights ranging from 550 mm (standard guardrail height) up to 660 mm. Hence, the new guardrail design provides approximately 110 mm (4.4 in.) of mounting height tolerance. When installed at the nominal mounting height of 635 mm, a 75-mm pavement overlay could be applied to the roadway without requiring adjustments to the barrier’s height.

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

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105190400105 ◽

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

Volume 9: Transportation Systems; Safety Engineering, Risk Analysis and Reliability Methods; Applied Stochastic Optimization, Uncertainty and Probability ◽

10.1115/imece2011-64483 ◽

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.

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

SIMULATION ◽

10.1177/0037549702078010001 ◽

2002 ◽

Vol 78 (10) ◽

pp. 587-599 ◽

Cited By ~ 16

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.

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Yacht Keels - An Experimental Study

10.5957/csys-1975-008 ◽

1975 ◽

Author(s):

Pierre DeSaix

Keyword(s):

Experimental Study ◽

Aspect Ratio ◽

Center Of Gravity ◽

Full Scale ◽

Optimum Size ◽

Hull Form ◽

Size And Shape ◽

Aspect Ratios ◽

Current Design ◽

Lateral Area

Model tests are presented for a series of nine keels; three aspect ratios, three sweep angles; all at constant lateral area, taper ratio and thickness ratio. The series is shown to bracket current design trends. These keels are all tested on the same canoe body, over a range of heel angles, lee-ways, and speeds. The results are presented in terms of full-scale sailing performance with due allowance for a reasonable ballast ratio and resulting vertical center of gravity for each keel. Optimum sweep angles for each aspect ratio are found. A second series of three keels, geometrically similar but varying in lateral area, is provided. Predictions of windward performance demonstrate the effect of keel size. An optimum size is found for three wind strengths. The results are for one hull form only. However, a method is suggested for estimating the effect of keel size and shape for any proposed design.

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A Sub-System Test Methodology for Simulating EEVC Side Impact

10.1115/imece2000-2484 ◽

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.

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A Base Study to Investigate MASH Conservativeness of Occupant Risk Evaluation

ASCE-ASME J Risk and Uncert in Engrg Sys Part B Mech Engrg ◽

10.1115/1.4045318 ◽

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.

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

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198196152800117 ◽

1996 ◽

Vol 1528 (1) ◽

pp. 155-160 ◽

Cited By ~ 9

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.

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Test Level 4 Bridge Rails

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1720-10 ◽

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.

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