2013 Session: 730

• Extended Validation of Finite Element Model for 2007 Chevrolet Silverado Pickup Truck
  Abstract: A finite element (FE) model based on a 2007 Chevrolet Silverado quad-cab pick-up truck was developed through the process of reverse engineering at the National Crash Analysis Center (NCAC) of The George Washington University (GWU). This detailed FE model was constructed to include full functional capabilities of the suspension and steering subsystems. This model was initially validated by comparing the simulation of the NCAP frontal wall impact with actual data from NHTSA tests for a comparable vehicle. This was supplemented with comparison to inertial and suspension response data that compared the vehicle before tear down to the FE model. Acceptable results of the initial validation led to the release of the FE model. Subsequently, interior elements were added to the model and additional validations were conducted. The first validation involved comparing data from other full frontal wall tests to the simulated test with the updated model. The model was also successfully validated against a side impact test. The robustness of the model was demonstrated by simulations of a centerline pole impact and damage consistency comparisons for rigid wall, offset deformable barrier, and centerline pole impacts at varying speeds. The simulations executed without error in these runs and the results reflected the expected responses and consistency with varying parameters. This led to the conclusion that the model was robust across various impact scenarios.
  Authors: Opiela, Kenneth Steven; Marzougui, Dhafer
  Authors: Opiela, Kenneth Steven; Marzougui, Dhafer
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-2565
• Extended Validation of Finite Element Model for 2010 Toyota Yaris Passenger Sedan
  Abstract: A finite element (FE) model based on a 2010 Toyota Yaris passenger sedan was developed through the process of reverse engineering at the National Crash Analysis Center (NCAC) of The George Washington University (GWU). The resulting FE vehicle model has 974,383 elements, without the interior components or restraint systems. This detailed FE model was constructed to include full functional capabilities of the suspension and steering subsystems. This model was validated by comparing the simulation of the NCAP frontal wall impact with actual data from NHTSA tests for comparable vehicles. Acceptable results of the initial validation led to the release of the FE model. Subsequently, validation efforts continued with comparisons to data from other full frontal wall and offset deformable barrier impacts. Simulation results compared well to data from these tests. Finally, model robustness was demonstrated by additional simulations of centerline pole impacts, full front and offset head-on collisions into a Chevrolet Silverado, and damage comparisons for impacts at varying speeds. The simulations executed without error in these runs and the results reflected the expected responses and consistency with varying parameters. This led to the conclusions that the model was robust across various impact scenarios.
  Authors: Opiela, Kenneth Steven; Marzougui, Dhafer
  Authors: Opiela, Kenneth Steven; Marzougui, Dhafer
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-2567
• Development Guidance for Minimum Sign Area for Slipbase Supports
  Abstract: This study seeks to establish a minimum sign area to be mounted on a slipbase system to reduce severity of the roof crush and improve safety according to the new safety-performance evaluation guidelines included in MASH. Computer simulation was used to help predict whether or not secondary contact between a support system and an impacting vehicle would occur, and the probable location of the contact. Full-scale crash testing MASH 3-61 (1100C passenger car) and 3-62 (2270P pickup truck) were conducted with the vehicles impacting the sign support at a speed of 62 mph. A 12 ft2 sign size was mounted on a BWG 10 T-bracket configuration #2 pipe support type. Test 3-61 resulted in a roof crush of 4.75 inches, which did not meet MASH criteria. After carefully reviewing and interpreting a new set of computer simulation results, researchers suggested 14 ft2 to be the minimum sign size for a slipbase support system. A new full scale crash test MASH 3-61 (1100C passenger car) was performed on a 14 ft2 sign area. The new test met the MASH criteria. It is recommended that signs with an area between 14 and 24 ft2 would be mounted on a BWG 10 pipe support with slipbase. All signs with an area smaller than 14 ft2 need to be mounted on a 13 BWG pole with a wedge and socket system. Sign areas between 24 and 36 ft2 should be mounted on a schedule 80 pipe support with a slipbase support system.
  Authors: Silvestri, Chiara; Arrington, Dusty; Bligh, Roger P.
  Authors: Silvestri, Chiara; Arrington, Dusty; Bligh, Roger P.
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-2620
• In-service Performance Evaluation of Cable Median Barriers on Florida’s Limited-Access Facilities
  Abstract: This paper presents a study to evaluate the safety performance of cable median barriers on limited access facilities in Florida. The safety evaluation was based on the percentages of barrier and median crossovers by vehicle type, crash severity, and cable median barrier type (CASS and Gibraltar systems). Twenty-three locations with cable median barriers totaling about 101 miles were identified. Police reports of 8,818 crashes from years 2003-2010 at these locations were reviewed to verify and obtain detailed crash information. A total of 549 crashes were determined to be cable median barrier related (i.e., crashes involving vehicles hitting the cable median barrier) and were reviewed in further detail to identify crossover crashes and the manner in which the vehicles crossed the barriers, i.e., either by over-riding, under-riding, or penetrating the barriers. A relatively low 2.6% of vehicles that hit the cable median barrier crossed the median and traversed into the opposite travel lane. Overall, 98.1% of cars and 95.5% of light trucks that hit the barrier were prevented from crossing the median. Further, 16.4% of barrier related crashes crossed over the barrier but did not cross the median. Overrides were found to be more severe compared to under-rides and penetrations. The statistics showed that the Gibraltar system experienced a higher proportion of penetrations compared to the CASS system. The CASS system resulted in a slightly higher percentage of moderate and minor injury crashes compared to the Gibraltar system.
  Authors: Alluri, Priyanka; Haleem, Kirolos M.; Gan, Albert
  Authors: Alluri, Priyanka; Haleem, Kirolos M.; Gan, Albert
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-0149
  Practice-Ready: Yes
• Safety-Effectiveness Evaluation of Cable Rail Systems in Tennessee
  Abstract: Performances and safety effectiveness evaluation results of median cable barrier systems in Tennessee are presented in this paper. Twenty seven segments with at least three years of complete crash data before and after cable installations were analyzed. The segments were evaluated in terms of descriptive statistics of factors associated with median crashes whose occurrences were influenced by the presence or absence of the median cable barriers. The cable systems were also evaluated in terms of percentage safety effectiveness and confidence levels comparing before and after cable conditions. The study involved review of crash hard copies where only 24% were found to be relevant for median cable barriers evaluation, 76% were not related. Descriptive statistics compared percentage of certain type of crashes, crash attributes and other elements to the total crashes before and after the barriers were installed. To evaluate the safety effectiveness, the research applied crash modeling in the form of safety performance models, and observational Empirical Bayes (EB) before and after analysis. Safety effectiveness of the installed median cable barrier systems was found to be 93% for fatal crashes, 85% for fatal and incapacitating injury crashes combined and 51% for the combination of fatal and all injury crashes all above 95% confidence level. Study also found that combined fatal and injury crashes were reduced by 21% after median cable installations while fatal crashes only were reduced by 80%. Total number of people killed or injured was reduced by 29% after installation.
  Authors: Chimba, Deo; Emaasit, Daniel; Allen, Steve; Hurst, Brian; Nelson, Marcie
  Authors: Chimba, Deo; Emaasit, Daniel; Allen, Steve; Hurst, Brian; Nelson, Marcie
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-0528
  Practice-Ready: Yes
• Crash Wall Design to Protect Mechanically Stabilized Earth Retaining Walls
  Abstract: Mechanically Stabilized Earth (MSE) retaining walls are used to provide roadway elevation for bridge approaches, underpass frontage roads and other roadway elevation applications. Vehicular traffic may exist on the high (fill) side of the MSE retaining wall, on the low side, or both sides. For traffic on the high side, a conventional traffic barrier might be placed on or near the top of the wall and mounted on a moment slab or a bridge deck. For traffic on the low side, a conventional traffic barrier might be installed adjacent to the wall or the wall itself may serve as the traffic barrier. Typical MSE wall panels are not designed to resist vehicle impacts. Therefore, structural damage to the wall panels and the earth fill would require complicated and expensive repairs. A simple reinforced concrete crash wall constructed in front of the MSE wall panels can significantly reduce damage to them. It may prove practical to implement such a design in order to reduce costly repair to the MSE wall structure.In this paper, LS-DYNA finite element analysis code was used to model and analyze a sacrificial crash wall design to determine its effectiveness of protecting the MSE retaining wall. Based on the LS-DYNA simulations, a 0.2 m. thick crash wall is considered adequately designed to reduce damage to the MSE wall.
  Authors: Abu-Odeh, Akram; Kim, Kang Mi
  Authors: Abu-Odeh, Akram; Kim, Kang Mi
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-5263
  Practice-Ready: Yes
• Design and Full-Scale Testing of Texas Department of Transportation Type T131RC Bridge Rail
  Abstract: Texas Department of Transportation (TXDOT) currently uses the TXDOT Type T101RC Bridge Rail. The T101RC bridge rail is a steel post and beam bridge rail anchored to the top of a concrete curb. The T101RC has been used extensively on older type bridges in retrofit bridge railing applications. This bridge rail is 27 inches in height and is anchored to the top of concrete curbs of varying heights. The heights of the posts and the number of bridge rail elements vary depending on the height of the concrete curb. The posts are anchored to the curb using four adhesive anchors. Based on crash testing of similar rail designs of the same height, the TXDOT Type T101RC Bridge Rail would not meet the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) Test Level 3 (TL-3) criteria. The purpose of this project was to design and crash test a modified design of the TXDOT T101RC Bridge Rail that would meet the strength and safety performance criteria for TL-3 of MASH. The TXDOT T131RC Bridge Rail design and tested for this project and presented herein met all the strength and safety performance criteria of MASH. This bridge rail is currently being used on new and retrofit applications in Texas. This paper presents the analytical results, details of the design, and full scale crash test results performed on the T131RC bridge rail design.
  Authors: Williams, William Frederick; Holt, John
  Authors: Williams, William Frederick; Holt, John
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-4675
  Practice-Ready: Yes
• In-service Performance Evaluation of Cable Median Barriers on Florida's Limited-Access Facilities
  Authors: Alluri, Priyanka
  Authors: Alluri, Priyanka
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design
  Session: 730
  Paper Number: 13-0149