scholarly journals A Comparative Analysis of Two Full-Scale MD-500 Helicopter Crash Tests

Author(s):  
Justin Littell
2000 ◽  
Author(s):  
Krishnakanth Aekbote ◽  
Srinivasan Sundararajan ◽  
Joseph A. Prater ◽  
Joe E. Abramczyk

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.


2018 ◽  
Vol 219 ◽  
pp. 02012
Author(s):  
Dawid Bruski ◽  
Stanisław Burzyński ◽  
Jacek Chróścielewski ◽  
Łukasz Pachocki ◽  
Krzysztof Wilde ◽  
...  

Road safety barriers are used to increase safety in potentially dangerous places on the roads. They are designed and installed on the roads to prevent any vehicle from getting outside the travelled way or from entering the opposite lane of the road. Barriers, which are used on European roads, have to undergo full scale crash tests according to the EN 1317 standards. Nowadays as a supplement to real crash tests, numerical simulations are commonly used. The work concerns the influence of position of the post or its absence on the crashworthiness of the cable barrier based on numerical study results.


Author(s):  
Scott K. Rosenbaugh ◽  
Ronald K. Faller ◽  
Jennifer D. Schmidt ◽  
Robert W. Bielenberg

Roadway resurfacing and overlay projects effectively reduce the height of roadside barriers placed adjacent to the roadway, which can negatively affect their crashworthiness. More recently, bridge rails and concrete barriers have been installed with slightly increased heights to account for future overlays. However, adjacent guardrails and approach transitions have not yet been modified to account for overlays. The objective of this project was to develop an increased-height approach guardrail transition (AGT) to be crashworthy both before and after roadway overlays of up to 3 in. The 34-in. tall, thrie-beam transition detailed here was designed such that the system would be at its nominal 31-in. height following a 3-in. roadway overlay. Additionally, the upstream end of the AGT incorporated a symmetric W-to-thrie transition segment that would be replaced by an asymmetric transition segment after an overlay to keep the W-beam guardrail upstream from the transition at its nominal 31-in. height. The 34-in. tall AGT was connected to a modified version of the standardized buttress to mitigate the risk of vehicle snag below the rail. The barrier system was evaluated through two full-scale crash tests in accordance with Test Level 3 (TL-3) of AASHTO’s Manual for Assessing Safety Hardware (MASH) and satisfied all safety performance criteria. Thus, the 34-in. tall AGT with modified transition buttress was determined to be crashworthy to MASH TL-3 standards. Finally, implementation guidance was provided for the 34-in. tall AGT and its crashworthy variations.


2012 ◽  
Vol 2309 (1) ◽  
pp. 94-104
Author(s):  
Robert W. Bielenberg ◽  
Karla A. Lechtenberg ◽  
Dean L. Sicking ◽  
Steve Arens ◽  
Ronald K. Faller ◽  
...  

A new fracturing-bolt universal breakaway steel post (UBSP) was developed and evaluated for use as a replacement for the controlled-release terminal (CRT) wood post currently used in the Thrie beam bullnose system. After numerous steel post concepts were investigated, a fracturing-bolt steel post was selected as the most promising design. The fracturing-bolt steel post successfully matched the strength and dynamic behavior of the CRT wood post in three impact orientations. The UBSP was incorporated into the Thrie beam bullnose barrier system and subjected to three full-scale vehicle crash tests according to the Test Level 3 guidelines provided in NCHRP Report 350. Test Designations 3–30, 3–31, and 3–38 were chosen to evaluate the performance of the Thrie beam bullnose system with UBSPs. All three full-scale crash tests demonstrated that the UBSP performed in a satisfactory manner in the bullnose system, as the vehicle was captured and safely brought to a controlled stop. On the basis of the successful completion of the three full-scale crash tests, it is recommended that the UBSP be considered a safe alternative to CRT posts in the original Thrie beam bullnose median barrier system. It is also noted that the performance of the UBSP suggests that it may have additional applications, including in long-span guardrail, end terminals, and guardrail in mow strips or encased in pavement.


2012 ◽  
Vol 490-495 ◽  
pp. 2676-2680
Author(s):  
Hong Jun Cui ◽  
Xiao Jing Shen ◽  
Yu Liu ◽  
Xi Xin Sun

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.


Author(s):  
Malcolm H. Ray

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.


Author(s):  
James C. Holloway ◽  
Dean L. Sicking ◽  
Ronald K. Faller

The safety performance of a 737-mm (29-in.)-high open concrete bridge railing was evaluated. The evaluation included four full-scale crash tests, investigating two critical impact locations where structural failure was most likely to occur. Each impact location was evaluated with a single-unit truck and a ballasted pickup truck. The safety performance of the 737-mm-high open concrete bridge rail was shown to meet the Performance Level 2 requirements specified in the AASHTO Guide Specifications for Bridge Railings (1989).


Author(s):  
Mojdeh Asadollahi Pajouh ◽  
Robert W. Bielenberg ◽  
John D. Reid ◽  
Jennifer D. Schmidt ◽  
Ronald K. Faller ◽  
...  

Portable concrete barriers (PCBs) are often used in applications in which limited deflection is desired during vehicle impacts, such as bridge decks and work zones. In an earlier study, a reduced-deflection, stiffening system was configured for use with non-anchored, F-shape PCBs and was successfully crash tested under Manual for Assessing Safety Hardware (MASH) safety performance criteria. However, details and guidance for implementing this barrier system outside the length-of-need, including within transitions to other barrier systems, were not provided. The focus of this study was to develop a crashworthy transition design between the reduced-deflection, F-shape PCB system to free-standing, F-shape PCB segments using engineering analysis and LS-DYNA computer simulation. First, the continuous steel tubes in the reduced-deflection system were tapered down to the surface of the free-standing PCB segments to reduce the potential for vehicle snag. In addition, steel tube spacers were added at the base of the two joints upstream from the reduced-deflection system to increase the stiffness of adjacent free-standing PCBs. Simulations were performed to determine the critical impact points for use in a full-scale crash testing program. It was recommended that three full-scale crash tests be conducted, two tests with a 2270P pickup truck vehicle and one test with an 1100C passenger car, to evaluate the proposed design system with impacts at the recommended critical impact points.


2017 ◽  
Vol 124 ◽  
pp. 04002
Author(s):  
Minsoo Jin ◽  
Sukki Lee ◽  
Wonil Park ◽  
Insong Park

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