Occupied Volume Integrity Testing: Elastic Test Results and Analyses

Carolan, Michael; Muhlanger, Michelle; Perlman, Benjamin; Tyrell, David

doi:10.1115/rtdf2011-67010

Cited by 3 publications

(7 citation statements)

References 4 publications

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“…At each location, a vertical, lateral, and longitudinal (VLL) array of string pots was installed between the ground and a bracket attached to the car. These arrays have been successfully used in previous quasistatic tests of passenger equipment to resolve the 3-dimensional motion of a point into its X, Y, and Z components [5]. Because the measurements made at locations with VLL arrays are less susceptible to errors due to off-axis motions, the longitudinal displacements from VLL arrays at each end of the car are used to describe the overall change in length of the car's underframe.…”

Section: Figure 6 Strain Gages On Structural Membersmentioning

confidence: 99%

“…During the previous testing program, two Budd Pioneer passenger railcars were loaded to crippling using a similar test setup as the M1 test [5]. In that program, the cars buckled at 1.15 and 1.2 million pounds, respectively.…”

Section: Figure 11 Post-test Overhead View Of Crippled Carmentioning

confidence: 99%

“…Additionally, this previous program demonstrated that the 1.2 million pound crippling load adopted by the ETF as one of its OVI criteria was a reasonable description of the minimum crippling load to be found in an 800-kip compliant railcar of conventional design. The progress of and results from the previous research program have been detailed in several recent publications [7], [8], [9].…”

Section: Introductionmentioning

confidence: 99%

“…Previously, FRA-sponsored research investigated the alternatively-evaluated OVI of two Budd Pioneer passenger railcars [5]. Similarly to the current program, the previous testing was conducted by Transportation Technology Center, Inc. [6].…”

Section: Introductionmentioning

confidence: 99%

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Crippling Test of a Budd M-1 Passenger Railcar: Test and Analysis Results

Carolan

Perlman

Tyrell

et al. 2014

2014 Joint Rail Conference

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The Federal Railroad Administration's (FRA) Office of Research and Development is conducting research into the occupied volume integrity (OVI) of passenger railcars. OVI refers to a passenger railcar's ability to preserve space for passengers and crew during accident loading conditions. The information developed in this research program will form the basis for establishing alternative OVI evaluation procedures. These alternative procedures, in turn, will allow a wider variety of passenger railcar designs to have their OVI evaluated, will provide guidance for applying modern engineering technologies, such as finite element analysis (FEA), and will continue to ensure a level of safety in evaluated vehicles equivalent to conventional evaluation.As part of this research program, two tests and corresponding FEA were conducted on a Budd M-1 passenger railcar that had been retrofitted with crash energy management (CEM) components on both ends. This testing and analysis program was sponsored by FRA and carried out by Transportation Technology Center, Inc. (TTCI), Arup, and the Volpe Center. An 800,000 pound load test was conducted on March 13, 2013 and was intended to elastically deform the car. The data generated during this test were, in turn, used to validate FE models of the M-1 car. The second test was performed on July 17, 2013. This test introduced loads into the occupant volume through its CEM attachment points until the ultimate, or crippling, load was reached. By loading the occupant volume through the CEM components, the test load path is similar to the load path that would be traveled by collision loads during activation of the CEM system. This paper presents the results of the crippling test, discusses the sequence of buckling that was observed to occur in the test, and compares the results of the test with the results from FEA of the test conditions. During the crippling test, the car exhibited a crippling load of 1.1 million pounds. This value is consistent with crippling loads reached by two Budd Pioneer cars that were previously tested in an FRA program. The buckling sequence of the members making up the M-1's occupant volume were particularly well-captured by strain gages during this most recent test. The load path through the occupant volume and the sequence of progressive buckling of structural members is discussed. Additionally, the presence of existing damage and previously-repaired areas and their likely effects on the crippling behavior of the car are discussed.

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Section: Figure 6 Strain Gages On Structural Membersmentioning

confidence: 99%

Section: Figure 11 Post-test Overhead View Of Crippled Carmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Crippling Test of a Budd M-1 Passenger Railcar: Test and Analysis Results

Carolan

Perlman

Tyrell

et al. 2014

2014 Joint Rail Conference

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“…An initial 800,000 pound compression test was performed in January, 2010 and discussed in Reference 4. Due to uncertainties in the results of this test and the discovery of localized damage to the test car, a second 800,000 pound compressive strength test was conducted on January 19, 2011 [8]. This test verified that the car was in a suitable condition to be used as the test article in the crippling test.…”

Section: Criteria and Proceduresmentioning

confidence: 99%

Crippling Test of a Budd Pioneer Passenger Car

Carolan

Perlman

Tyrell

2012

2012 Joint Rail Conference

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This research program was sponsored by the Federal Railroad Administration (FRA) Office of Research and Development in support of the advancement of improved safety standards for passenger rail vehicles.FRA and the Volpe National Transportation Systems Center (Volpe Center) have conducted a research program to develop alternative methods for demonstrating occupied volume integrity (OVI) of passenger rail cars using a combination of testing and analysis. Previous publications have addressed the planning and progress of a series of tests intended to examine the collision load path through the occupant volume of passenger cars equipped with crash energy management (CEM) systems. This program has included an elastic 800-kip buff strength test, two quasi-static tests that loaded a passenger car to its ultimate (crippling) capacity, and corresponding finite element (FE) analyses of each test. This paper discusses the two crippling tests and the companion FE analyses.One alternative method for evaluating OVI moves the applied loads from the line of draft to the collision load path. This alternative methodology also permits a combination of testing and analysis to be used to demonstrate the car's OVI, in contrast to the conventional methodology (as prescribed in existing FRA regulations) which only permits testing. The alternative methodology was adopted as the recommendations developed by the Railroad Safety Advisory Committee's (RSAC) Engineering Task Force (ETF) in its "Technical Criteria and Procedures for Evaluating the Crashworthiness and Occupant Protection Performance of Alternatively-Designed Passenger Rail Equipment for Use in Tier I Service." The research program was undertaken to verify the efficacy of using a combination of elastic testing and plastic analysis to evaluate the OVI of a passenger car loaded along its collision load path as prescribed in the ETF report. Earlier in this research program an elastic test of a BuddPioneer car was used to validate an FE model of the car, per the ETF's procedures. This model was then modified to reflect the condition of the car in its crippling test configuration. The model was used to simulate the crippling behavior of the car, following the ETF's procedures. Two Pioneer cars were then tested to crippling to provide additional data to validate the FE model and the proposed alternative OVI evaluation.Because the test cars used in this research program were equipped with CEM systems, the alternative evaluation loads were placed at the locations where the energy-absorbing components attached to the occupant volume. During both crippling tests, loads were measured at each energy-absorber support location on the live and restrained ends of the car. Additional instrumentation used in the second crippling test included strain gages on the major longitudinal structural members, displacement transducers at each load location, and vertical, lateral, and longitudinal displacement transducers on the underframe of the car. The results of the FE analysis compare favorabl...

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Research on Calculation Method for Maximum Mean Acceleration in Longitudinal Train Collision

Zhang

Wang

Zhu

et al. 2021

Shock and Vibration

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A large number of numerical simulations are required to design an energy absorption scheme for train crashworthiness, leading to low design efficiency in the early stage. Based on train collision dynamics theory and the finite element method, a dynamic finite element model of longitudinal train collision is established. According to the model, we studied the acceleration time-history characteristics during the train collision process, obtained the mean-peak ratio coefficient, and determined the calculation formula for the maximum mean acceleration of a longitudinal train collision. Through characteristic analysis of the vehicle acceleration, interface force, and other parameters during a longitudinal train collision, the calculation method of the mean acceleration was improved. The analysis shows that the maximum mean acceleration depends on two stages in the collision process: (1) the coupler action of the head vehicle: the mean-peak ratio coefficient of the head vehicle is 0.7 in this stage, and the mean-peak ratio coefficient of other vehicles is 0.43; (2) the coupler of the collision interface is cut off, and the energy absorption devices of the head vehicle or intermediate vehicle absorb energy; the mean-peak ratio coefficient of the vehicle is 0.93 in this stage. On this basis, a mathematical function is established describing the mean acceleration of the vehicle and the average crushing force of the coupler collapse tube and the energy-absorbing device. The calculation formula is obtained for the maximum mean acceleration of the longitudinal train collision, and the results are compared with the mean acceleration obtained by numerical simulation. The Kruskal–Wallis ANOVA multisample independent nonparametric test was conducted to verify the reliability of the calculation results in the 95% confidence interval. The calculation formula can be used to calculate the maximum mean acceleration in the energy allocation stage of train crashworthiness design to effectively improve the efficiency of train collision energy allocation.

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Occupied Volume Integrity Testing: Elastic Test Results and Analyses

Cited by 3 publications

References 4 publications

Crippling Test of a Budd M-1 Passenger Railcar: Test and Analysis Results

Crippling Test of a Budd M-1 Passenger Railcar: Test and Analysis Results

Crippling Test of a Budd Pioneer Passenger Car

Research on Calculation Method for Maximum Mean Acceleration in Longitudinal Train Collision

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