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    Design and validation of a 30,000 kg heavy goods vehicle using LS-DYNA
    (Amer Soc Mechanical Engineers, 2005) Atahan, Ali O.; Bonin, Guido; El-Gindy, Moustafa
    Extraordinary developments in virtual crash testing research have been achieved during the past decade. Advancements in hardware and software technology along with improvements in computation mechanics and increased number of full-scale crash tests contributed positively to the development of more realistic finite element models. Use of complex finite element codes based on computational mechanics principles allowed the virtual reproduction of real world problems. Regarding roadside safety, the design phase was, until now, based on the use of simplified analysis, unable to describe accurately the complexity of vehicle impacts against safety hardware. Modeling details, such as geometry, constitutive laws of the materials, rigid, kinematic and other links between bodies, definition and characterization of contact surfaces are necessary to build an accurate finite element model for an impact problem. This set of information is needed for each different body involved in the event; making the development of a complete model very much demanding. Once a part (subset) of the entire model has been accurately validated against real experimental data, it can be used again and again in other analogous models.
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    Development of a draft heavy vehicle rear underride guard specification
    (American Society of Mechanical Engineers (ASME), 2006) Atahan, Ali O.; El-Gindy, Moustafa; Bonin, Guido; Allen, James
    This paper summarizes results of a large research program intended to develop a draft rear underride guard specification for heavy vehicles. Results of a series of laboratory and full-scale crash tests performed at the Transport Canada Research Center were used in the development of these specifications. A total of eleven full-scale crash tests was carried out to evaluate the effectiveness of different underride guards. The first ten of these tests were performed on a simulated trailer attached guard. Four different underride guard designs were used in these ten full-scale crash tests. Three different vehicle models traveling at 48, 56 and 65 km/h speeds were used to impact underride guards head on. Results of the first ten crash tests show that the currently used US FMVSS 223 standard is far from adequate in preventing the occurrance of rear underride. Based on findings obtained from these crash tests, an improved guard design was developed and tested using a 16-meter trailer. This final crash test verified the effectiveness of improved guard design in reducing the undesirable effects of rear underride crashes. Based on the results, a draft heavy vehicle rear underride guard specification was developed. Copyright © 2006 by ASME.
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    EVALUATION OF VERTICAL WALL-TO-GUARDRAIL TRANSITION
    (Amer Soc Mechanical Engineers, 2009) Atahan, Ali O.; Bonin, Guido; El-Gindy, Moustafa
    Transition barriers are used to connect longitudinal barriers that have different stiffnesses. They are designed to provide a gradual increase in stiffness towards the stiffer barrier section. In this study, a W-beam rail and a W-beam rubrail transition connecting a rigid bridge rail to a semi-rigid guardrail was evaluated using numerical and experimental methods. First, a finite element model of the transition design was constructed and validated using a 2000 kg pickup truck impact. Then, a series of vehicle models, i.e., 900 kg compact automobile, 8000 kg single unit truck and finally 30,000 kg heavy truck was used to evaluate the impact performance of the same transition design numerically. Simulation results predict that the double W-beam transition barrier performs acceptably in containing and redirecting all vehicles except 30,000 kg heavy truck. Occupant injury criteria were also found to be acceptable for all the cases, except 30,000 kg truck impact. Performing further simulations with vehicle sizes heavier than 8,000 kg that exist in crash testing guidelines is recommended to evaluate the acceptability limit of existing W-beam rail and a W-beam rubrail transition.
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    Evaluation of vertical wall-to-guardrail transition
    (2008) Atahan, Ali O.; Bonin, Guido; El-Gindy, Moustafa
    Transition barriers are used to connect longitudinal barriers that have different stiffnesses. They are designed to provide a gradual increase in stiffness towards the stiffer barrier section. In this study, a W-beam rail and a W-beam rubrail transition connecting a rigid bridge rail to a semi-rigid guardrail was evaluated using numerical and experimental methods. First, a finite element model of the transition design was constructed and validated using a 2000 kg pickup truck impact. Then, a series of vehicle models, i.e., 900 kg compact automobile, 8000 kg single unit truck and finally 30,000 kg heavy truck was used to evaluate the impact performance of the same transition design numerically. Simulation results predict that the double W-beam transition barrier performs acceptably in containing and redirecting all vehicles except 30,000 kg heavy truck. Occupant injury criteria were also found to be acceptable for all the cases, except 30,000 kg truck impact. Performing further simulations with vehicle sizes heavier than 8,000 kg that exist in crash testing guidelines is recommended to evaluate the acceptability limit of existing W-beam rail and a W-beam rubrail transition. Copyright © 2008 by ASME.
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    A rear-end protection device for heavy vehicles
    (American Society of Mechanical Engineers (ASME), 2003) Atahan, Ali O.; Joshi, Abhishek S.; El-Gindy, Moustafa
    Rear underride crashes, particularly with heavy vehicles, constitute a serious safety concern for passenger cars. Several solutions to this emerging concern have been proposed by responsible agencies. Recent rear-end crashes with heavy vehicles show that a properly used rear underride guard devices can slow down impacting vehicle in a controlled manner. Moreover, with the use of these devices, the severity of crashes can be reduced and loss of lives can be prevented. In this paper, a special underride guard device is designed for heavy vehicle use. The height of the device from ground and support conditions are varied to evaluate and compare the crash performances. Finite element models of these particular designs are constructed and models are impacted by a passenger car model traveling at two different speeds of 48 km/h and 64 km/h. LS-DYNA, a non-linear finite element code capable of analyzing large deformations is used for the analysis. Vehicle decelerations, energy dissipations and passenger car crush characteristics are compared to determine the acceptability of each design. Based on the simulation study, an optimum height from ground and support condition are determined for acceptable impact performance for heavy vehicle mounted rear-end underride guard devices against passenger vehicle impacts.