Finite-Element Crash Test Simulation of New York Portable Concrete Barrier with I-Shaped Connector

2006 ◽  
Vol 132 (3) ◽  
pp. 430-440 ◽  
Author(s):  
Ali O. Atahan
2012 ◽  
Vol 2309 (1) ◽  
pp. 114-126 ◽  
Author(s):  
Dhafer Marzougui ◽  
Cing-Dao (Steve) Kan ◽  
Kenneth S. Opiela

The National Crash Analysis Center (NCAC) at the George Washington University simulated the crash of a 2,270-kg Chevrolet Silverado pickup truck into a standard 32-in. New Jersey shape concrete barrier under the requirements of Test 3–11 of the Manual for Assessing Safety Hardware (MASH). The new, detailed finite element (FE) model for the Chevrolet Silverado was used as the surrogate for the MASH 2270P test vehicle. An FE model of the New Jersey barrier was drawn from the array of NCAC hardware models. The primary objective of this analysis was to simulate the crash test conducted to evaluate how this commonly used, NCHRP 350–approved device would perform under the more rigorous MASH crashworthiness criteria. A secondary objective was to use newly developed verification and validation (V&V) procedures to compare the results of the detailed simulation with the results of crash tests undertaken as part of another project. The crash simulation was successfully executed with the detailed Silverado FE model and NCAC models of the New Jersey concrete barrier. Traditional comparisons of the simulation results and the data derived from the crash test suggested that the modeling provided viable results. Further comparisons employing the V&V procedures provided a structured assessment across multiple factors reflected in the phenomena importance ranking table. Statistical measures of the accuracy of the test in comparison with simulation results provided a more robust validation than previous approaches. These comparisons further confirmed that the model was able to replicate impacts with a 2270P vehicle, as required by MASH.


SIMULATION ◽  
2002 ◽  
Vol 78 (10) ◽  
pp. 587-599 ◽  
Author(s):  
Ali O. Atahan

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.


2016 ◽  
Vol 56 (6) ◽  
pp. 455-461
Author(s):  
Raissa Likhonina

This paper deals with a FEA simulation of the vehicle crash with steel safety barriers in ANSYS LS-DYNA® 15.0. Two types of safety barriers are used: JSNH4/H2 and JSAM-2/H2. A geometrical model of the barrier in the Modeler ANSYS® Workbench™ 15.0 was created and after that it was transformed into LS-DYNA® 15.0 to complete the crash test simulation. After computation in solver ANSYS LS-DYNA® 15.0 the results of the simulation such as impact forces, a body displacement and an integral energy were analyzed.


Author(s):  
Hilda B. Klasky ◽  
B. Richard Bass ◽  
Terry L. Dickson ◽  
Sarma B. Gorti ◽  
Randy K. Nanstad ◽  
...  

The Oak Ridge National Laboratory (ORNL) performed a detailed technical review of the 2015 Electrabel (EBL) Safety Cases prepared for the Belgium reactor pressure vessels (RPVs) at Doel 3 and Tihange 2 (D3/T2). The Federal Agency for Nuclear Control (FANC) in Belgium commissioned ORNL to provide a thorough assessment of the existing safety margins against cracking of the RPVs due to the presence of almost laminar flaws found in each RPV. Initial efforts focused on surveying relevant literature that provided necessary background knowledge on the issues related to the quasi-laminar flaws observed in D3/T2 reactors. Next, ORNL proceeded to develop an independent quantitative assessment of the entire flaw population in the two Belgian reactors according to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI, Appendix G, “Fracture Toughness Criteria for Protection Against Failure,” New York (both 1992 and 2004 versions). That screening assessment of the EBL-characterized flaws in D3/T2 used ORNL tools, methodologies, and the ASME Code Case N-848, “Alternative Characterization Rules for Quasi-Laminar Flaws”. Results and conclusions derived from comparisons of the ORNL flaw acceptance assessments of D3/T2 with those from the 2015 EBL Safety Cases are presented in the paper. The ORNL screening analyses identified fewer flaws than EBL that were not compliant with the ASME Section XI (1992) criterion; the EBL criterion imposed additional conservatisms not included in ASME Section XI. Furthermore, ORNL’s application of the updated ASME Section XI (2004) criterion produced only four non-compliant flaws, all due to design-basis loss-of-coolant loading transients. Among the latter, only one flaw remained non-compliant when analyzed using the warm-prestress (WPS) cleavage fracture model typically applied in USA flaw assessments. ORNL’s independent refined analysis of that flaw (#1660, which was also non-compliant in the EBL screening assessments) rendered it compliant when modeled as a more realistic individual quasi-laminar flaw using a 3-dimensional XFEM (eXtended Finite Element Method) approach available in the ABAQUS© finite element code. Taken as a whole, the ORNL-specific results and conclusions confirmed the structural integrity of Doel 3 and Tihange 2 under all design transients with ample margin in the presence of the 16,196 detected flaws.


Author(s):  
Anand Hammad ◽  
Anil Kalra ◽  
Prashant Khandelwal ◽  
Xin Jin ◽  
King H. Yang

Injuries to the upper extremities that are caused by dynamic impacts in crashes, including contact with internal instrument panels, has been a major concern, especially for smaller female occupants, and the problem worsens with increasing age due to reduced strength of the bones. From the analysis of 1988–2010 CDS unweighted data, it was found that risk of AIS ≥ 2 level for the arm was 58.2±20.6 percent higher in females than males, and the injury risk for a 75-year-old female occupant relative to a 21-year-old subjected to a similar physical insult was 4.2 times higher. Although injuries to upper extremities are typically not fatal, they can have long-term effects on overall quality of life. Therefore, it is important to minimize risks of injuries related to upper extremities, especially for elderly females, who are most at risk. Current anthropomorphic surrogates, like crash-test dummies, cannot be directly used to study injury limits, as these dummies were developed mainly to represent the younger population. The current study is focused on the development of a finite element (FE) model representing the upper extremity of an elderly female. This can be further used to analyze the injury mechanisms and tolerance limits for this vulnerable population. The FE mesh was developed through Computer Tomography (CT) scanned images of an elderly female cadaver, and the data included for validation of the developed model were taken from the experimental studies published in scientific literature, but only the data directly representing elderly females were used. It was found that the developed model could predict fractures in the long bones of elderly female specimens and could be further used for analyzing injury tolerances for this population. Further, it was determined that the developed segmental model could be integrated with the whole body FE model of the elderly female.


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):  
Sedat Ozcanan ◽  
Ali Osman Atahan

For guardrail designers, it is essential to achieve a crashworthy and optimal system design. One of the most critical parameters for an optimal road restraint system is the post embedment depth or the post-to-soil interaction. This study aims to assess the optimum post embedment depth values of three different guardrail posts embedded in soil with varying density. Posts were subjected to dynamic impact loads in the field while a detailed finite element study was performed to construct accurate models for the post–soil interaction. It is well-known that experimental tests and simulations are costly and time-consuming. Therefore, to reduce the computational cost of optimization, radial basis function–based metamodeling methodology was employed to create surrogate models that were used to replace the expensive three-dimensional finite element models. In order to establish the radial basis function model, samples were derived using the full factorial design. Afterward, radial basis function–based metamodels were generated from the derived data and objective functions performed using finite element analysis. The accuracy of the metamodels were validated by k-fold cross-validation, then optimized using multi-objective genetic algorithm. After optimum embedment depths were obtained, finite element simulations of the results were compared with full-scale crash test results. In comparison with the actual post embedment depths, optimal post embedment depths provided significant economic advantages without compromising safety and crashworthiness. It is concluded that the optimum post embedment depths provide an economic advantage of up to 17.89%, 36.75%, and 43.09% for C, S, and H types of post, respectively, when compared to actual post embedment depths.


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