Comparison of Methodologies for Finite Element Model Validation of Railroad Tank Car Side Impact Tests

2020 ◽  
Author(s):  
Shaun Eshraghi ◽  
Michael Carolan ◽  
Benjamin Perlman ◽  
Francisco González
Keyword(s):  
Finite Element ◽  
Model Validation ◽  
Full Scale ◽  
Impact Testing ◽  
Material Behavior ◽  
Side Impact ◽  
Impact Tests ◽  
Dynamic Impacts ◽  
Simulation Results ◽  
National Cooperative

Abstract The U.S. Department of Transportation’s Federal Railroad Administration (FRA) has sponsored a series of full-scale dynamic shell impact tests on railroad tank cars. For each shell impact test a pre-test finite element (FE) model is created to predict the overall force-time or force-displacement histories of the impactor, puncture/non-puncture outcomes of the impacted tank shell, global motions of the tank car, internal pressures within the tank, and the energy absorbed by the tank during the impact. While qualitative comparisons (e.g. the shapes of the indentation) and quantitative comparisons (e.g. peak impact forces) have been made between tests and simulations, there are currently no standards or guidelines on how to compare the simulation results with the test results, or what measurable level of agreement would be an acceptable demonstration of model validation. It is desirable that a framework for model validation, including well-defined criteria for comparison, be developed or adopted if FE analysis is to be used without companion full-scale shell impact testing for future tank car development. One of the challenges to developing model validation criteria and procedures for tank car shell puncture is the number of complex behaviors encountered in this problem, and the variety of approaches that could be used in simulating these behaviors. The FE models used to simulate tank car shell impacts include several complex behaviors, which increase the level of uncertainty in simulation results, including dynamic impacts, non-linear steel material behavior, two-phase (water and air) fluid-structure interaction, and contact between rigid and deformable bodies. Approaches to model validation employed in other areas of transportation where validation procedures have been documented are applied to railroad tank car dynamic shell impact FE simulation results. This work compares and contrasts two model validation programs: Roadside Safety Verification and Validation Program (RSVVP) and Correlation and Analysis Plus (CORA). RSVVP and CORA are used to apply validation metrics and ratings specified by the National Cooperative Highway Research Program Project 22-24 (NCHRP 22-24) and ISO/TS 18571:2014 respectively. The validation methods are applied to recently-completed shell impact tests on two different types of railroad tank cars sponsored by the FRA. Additionally, this paper includes discussion on model validation difficulties unique to dynamic impacts involving puncture.

scholarly journals Validation of Puncture Simulations of Railroad Tank Cars Using Full-Scale Impact Test Data

2018 ◽  
Author(s):  
Michael Carolan ◽  
Benjamin Perlman ◽  
Francisco González
Keyword(s):  
Model Validation ◽  
Transportation Systems ◽  
Full Scale ◽  
Impact Testing ◽  
Material Behavior ◽  
Fe Model ◽  
Impact Tests ◽  
Validation Criteria ◽  
Simulation Results ◽  
The Impact

The U.S. Department of Transportation’s Federal Railroad Administration (FRA) has sponsored a series of full-scale dynamic shell impact tests to railroad tank cars. Currently, there are no required finite element (FE) model validation criteria or procedures in the field of railroad tank car puncture testing and simulation. Within the shell impact testing program sponsored by FRA, comparisons made between test measurements and simulation results have included the overall force-time or force-indentation histories, the puncture/non-puncture outcomes, the rigid body motions of the tank car, the internal pressures within the lading, and the energy absorbed by the tank during the impact. While qualitative comparisons (e.g. the shapes of the indentation) and quantitative comparisons (e.g. peak impact forces) have been made between tests and simulations, there are currently no requirements or guidelines on which specific behaviors should be compared, or what measurable level of agreement would be acceptable demonstration of model validation. It is desirable that a framework for model validation, including well-defined criteria for comparison, be developed or adopted if simulation is to be used without companion shell impact testing for future tank car development. One of the challenges to developing model validation criteria and procedures for tank car shell puncture is the number of complex behaviors encountered in this problem, and the variety of approaches that could be used in simulating these behaviors. The FE models used to simulate tank car shell impacts include several complex behaviors, each of which can introduce uncertainty into the overall response of the model. These behaviors include dynamic impacts, non-linear steel material behavior, including ductile tearing, two-phase (water and air) fluid-structure interaction, and contact between rigid and deformable bodies. Several candidate qualitative and quantitative comparisons of test measurements and simulations results are discussed in this paper. They are applied to two recently-completed shell impact tests of railroad tank cars sponsored by FRA. For each test, companion FE simulation was performed by the Volpe National Transportation Systems Center. The process of FE model development, including material characterization, is discussed in detail for each FE model. For each test, the test objectives, procedures, and key instrumentation are summarized. For each set of test and simulations, several corresponding results are compared between the test measurements and the simulation results. Additionally, this paper includes discussion of approaches to model validation employed in other industries or areas of transportation where similar modeling aspects have been encountered.

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

1996 ◽  
Vol 1528 (1) ◽  
pp. 155-160 ◽  
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.

Advances in the Railroad Locomotive Crashworthiness

2003 ◽  
Author(s):  
Swamidas Punwani ◽  
Gopal Samavedam ◽  
Steve Kokkins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Strength ◽  
Full Scale ◽  
Fuel Tank ◽  
Structural Components ◽  
Dynamic Impact ◽  
Element Analysis ◽  
Simulation Results ◽  
Full Scale Tests

The paper describes locomotive and fuel tank crashworthiness research being conducted by the Federal Railroad Administration for improved safety of the locomotive crew under collision scenarios. The research involves static and dynamic impact strength evaluations of locomotive structural components. These evaluations which are based on full scale tests and simulations using finite element analysis are described in this paper. Correlations between the test and simulation results are also presented in some cases.

3413 Behaviors of Occupant Seated in Child Restraint Systems in Various Full-Scale Vehicle Side Impact Tests

2012 ◽  
Vol 2012.21 (0) ◽  
pp. 169-172
Author(s):  
Daisuke Yamaguchi ◽  
Yoshinori Tanaka ◽  
Naruyuki Hosokawa ◽  
Yasuhiro Matsui ◽  
Koji Mizuno ◽  
...  
Keyword(s):  
Full Scale ◽  
Side Impact ◽  
Impact Tests ◽  
Child Restraint

Full-Scale Wrinkling Tests and Analyses of Large Diameter Corroded Pipes

1998 ◽  
Author(s):  
Marina Q. Smith ◽  
Daniel P. Nicolella ◽  
Christopher J. Waldhart
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Axial Compression ◽  
Wall Thickness ◽  
Full Scale ◽  
Operating Conditions ◽  
Material Behavior ◽  
Combined Loading ◽  
Longitudinal Bending ◽  
Full Scale Tests

The aging of pipeline infrastructures has increased concern for the integrity of pipelines exhibiting non-perforating wall loss and settlement induced bending. While pressure based guidelines exist which allow pipeline operators to define operational margins of safety against rupture (e.g.; ANSI/ASME B31-G and RSTRENG (Battelle, 1989)), reliable procedures for the prediction of wrinkling in degraded pipes subjected to combined loading are virtually non-existent. This paper describes full-scale testing and finite element investigations performed in support of the development of accurate wrinkling prediction procedures for the Alyeska Pipeline Service Company. The procedures are applicable to corroded pipes subjected to combined loading such as longitudinal bending, internal pressure, and axial compression. During the test program, full-scale 48-inch diameter sections of the trans-Alaska pipeline were subjected to internal pressure and loads designed to simulate longitudinal bending from settlement, axial compression from the transport of hot oil, and the axial restraint present in buried pipe. Load magnitudes were designed based on normal and maximum operating conditions. Corrosion in the pipe section is simulated by mechanically reducing the wall thickness of the pipe. The size and depth of the thinned region is defined prior to each test, and attempts to bound the dimensions of depth, axial length, and hoop length for the general corrosion observed in-service. The analytical program utilizes finite element analyses that include the nonlinear anisotropic material behavior of the pipe steel through use of a multilinear kinematic hardening plasticity model. As in the tests, corrosion is simulated in the analyses by a section of reduced wall thickness, and loads and boundary constraints applied to the numerical model exactly emulate those applied in the full-scale tests. Verification of the model accuracy is established through a critical comparison of the simulated pipe structural behavior and the full-scale tests. Results of the comparisons show good correlation with measurements of the pipe curvature, deflections, and moment capacity at wrinkling. The validated analysis procedure is subsequently used to conduct parameter studies, the results of which complete a database of wrinkling conditions for a variety of corrosion sizes and loading conditions.

Characterizing Guardrail Steel for LS-DYNA3D Simulations

1996 ◽  
Vol 1528 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Amy E. Wright ◽  
Malcolm H. Ray
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Material Behavior ◽  
Finite Element Models ◽  
Type Ii ◽  
Material Models ◽  
Class A ◽  
Model Geometry ◽  
Simulation Results ◽  
Roadside Hardware

Finite-element models have three parts: geometry, connections, and material properties. As the visible parts of a model, geometry and connections are generally carefully considered. Material properties often are not chosen with the same degree of care although they are equally important to obtaining good results. Accurate simulations of vehicles striking roadside hardware require an understanding of both the material behavior and the mathematical material models in LS-DYNA3D. A method for comparing LS-DYNA3D simulations with typical ASTM materials tests is described. The behavior and modeling parameters of guardrail steel (AASHTO M-180 Class A Type II) are examined in this study. Experimental and simulation results of quasistatic coupon tests are compared for AASHTO M-180 Class A Type II guardrail steel, and parameters for guardrail steel are recommended.

Energy-Based Crashworthiness Optimization for Multiple Vehicle Impacts

2004 ◽  
Author(s):  
H. Fang ◽  
K. Solanki ◽  
M. F. Horstemeyer
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Absorption Capacity ◽  
Full Scale ◽  
Side Impact ◽  
Frontal Impact ◽  
Vehicle Model ◽  
Energy Absorption Capacity ◽  
Side Impacts ◽  
Design Variables

In this paper, we use a full-scale finite element vehicle model of a 1996 Dodge Neon in simulating two types of vehicle crashes, offset-frontal and side impacts. Based on an analysis of the vehicle’s histories of internal energy absorption under both impacts, we select twenty components as design variables in the optimization of the vehicle’s weight without decreasing the vehicle’s energy absorption capacity and energy absorption rate. We use the second-order polynomials in creating the metamodels for the response functions of energy absorption under both impacts. The optimization result shows a significant reduction on the total weight of the selected components. The LS-DYNA MPP v970 and a full-scale finite element vehicle model of 320,872 nodes and 577,524 elements are used in the simulations. A simulation of 100 ms offset-frontal impact takes approximately 17 hours with 36 processors on the IBM Linux SuperCluster, which has a total of 1038 Intel Pentium III 1.266 GHz processors and 607.5 GB RAM. A simulation of 100 ms side impact takes approximately 29 hours with the same condition as the offset-frontal simulation.

A Methodology of Side Impact Sled Test in MADYMO

2013 ◽  
Vol 779-780 ◽  
pp. 1110-1116
Author(s):  
Zhi Xiong Ma ◽  
Li Ping Dong ◽  
Xi Chan Zhu
Keyword(s):  
Model Validation ◽  
Impact Test ◽  
Full Scale ◽  
Side Impact ◽  
Sled Test

This paper put forward a new methodology of side impact sled test that separated an indoor panel into several parts and parameterized every parts speed curve getting from full scale side MDB impact test and reconstructed every parts motion using parametric speed curve in MADYMO. The advantage of this methodology is that the model validation is simplified and all side dummys injury values according to side impact sled test are very coincident with that according to full scale side MDB impact test.

Detailed Impact Analyses for Development of the Next Generation Rail Tank Car: Part 1—Model Development and Assessment of Existing Tank Car Designs

2009 ◽  
Author(s):  
Steven W. Kirkpatrick
Keyword(s):  
Finite Element ◽  
Model Development ◽  
Element Model ◽  
Full Scale ◽  
Severe Accident ◽  
Puncture Resistance ◽  
Impact Tests ◽  
Current Design ◽  
Accident Conditions ◽  
High Level

Significant research has been conducted over the past few years to develop improved railroad tank cars that maintain tank integrity for more severe accident conditions than current equipment. The approach taken in performing this research is to define critical collision conditions, evaluate the behavior of current design equipment in these scenarios, and develop alternative strategies for increasing the puncture resistance. The evaluations are being performed with finite element models of the tank cars incorporating a high level of detail. Both laboratory scale and full-scale impact tests were performed to validate the modeling and ultimately compare the effectiveness of current and alternative equipment designs. This paper describes the development of the detailed finite element model of the tank car and the use of the model for impact and puncture analyses. The validation of the model using the results of the full-scale impact tests is presented. The subsequent application of the model to assess the puncture resistance of existing tank car designs is discussed.

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