scholarly journals Finite Element Analysis of the Passenger Rail Equipment Workstation Table Sled Test

2018 ◽  
Author(s):  
Shaun Eshraghi ◽  
Kristine Severson ◽  
David Hynd ◽  
A. Benjamin Perlman
Keyword(s):  
Finite Element ◽  
Public Transportation ◽  
Contact Forces ◽  
Fe Model ◽  
Safety Standard ◽  
Sled Test ◽  
Passenger Rail ◽  
Hybrid Iii ◽  
Energy Absorbing ◽  
The U.S

Fixed workstation tables in passenger rail coaches can pose a potential injury hazard for passengers seated at them during an accident. Tables designed to absorb impact energy while minimizing contact forces can reduce the risk of serious injury, while helping to compartmentalize occupants during a train collision. The Rail Safety and Standards Board (RSSB) in the U.K. issued safety requirement GM/RT2100, Issue 5 [1] and the American Public Transportation Association (APTA) in the U.S. issued safety standard APTA PR-CS-S-018-13, Rev. 1 [2] with the goals of setting design and performance requirements for energy-absorbing workstation tables. The U.S. Department of Transportation, Federal Railroad Administration (FRA) Office of Research, Development and Technology directed the Volpe National Transportation Systems Center (Volpe Center) to evaluate the performance of the Hybrid-III Rail Safety (H3-RS) anthropomorphic test device (ATD), also known as a test dummy, in the APTA sled test in order to incorporate a reference to the H3-RS in the safety standard. The Volpe Center contracted with the manufacturer of the H3-RS, Transport Research Laboratory (TRL), in the U.K. to conduct a series of sled tests [3] with energy-absorbing tables, donated by various table manufacturers. The tables were either already compliant with the RSSB table standard or were being developed to comply with the APTA table standard. The sled test specified in Option A of the APTA table standard involves the use of two different 50th percentile male frontal impact ATDs. The H3-RS and the standard Hybrid-III (H3-50M) ATDs performed as expected. The H3-RS, which features bilateral deflection sensors in the chest and abdomen, was able to measure abdomen deflections while the H3-50M, which features a single sensor measuring chest compression, was not equipped to measure abdomen deflection. This study attempts to validate a finite element (FE) model of the APTA 8G sled test with respect to the thorax response of the H3-RS and H3-50M. The model uses a simplified rigid body-spring representation of one of the energy absorbing tables tested by TRL. The FE models of the H3-RS ATD and the H3-50M ATD were provided by TRL and LSTC, respectively. Results from the sled tests and FE simulations are compared using data obtained from the chest accelerometer, the chest and abdomen deflection sensors, and the femur load cells. Using video analysis, the gross motion of the dummies and table are also compared. Technical challenges related to model validation of the 8G sled test are also discussed. This study builds on previous analyses conducted to validate the abdomen response of the H3-RS FE model, which are presented in a companion paper [4].

scholarly journals Finite Element Model Validation of the Hybrid-III Rail Safety (H3-RS) Anthropomorphic Test Device (ATD)

2018 ◽  
Author(s):  
Shaun Eshraghi ◽  
Kristine Severson ◽  
David Hynd ◽  
A. Benjamin Perlman
Keyword(s):  
Finite Element ◽  
Public Transportation ◽  
Crash Test ◽  
Fe Model ◽  
Test Device ◽  
Sled Test ◽  
Impact Tests ◽  
Hybrid Iii ◽  
Pendulum Impact ◽  
Vertical Impact

The Hybrid-III Rail Safety (H3-RS) anthropomorphic test device (ATD), also known as a crash test dummy, was developed by the Rail Safety and Standards Board (RSSB), DeltaRail (now Resonate Group Ltd.), and the Transport Research Laboratory (TRL) in the United Kingdom between 2002 and 2005 for passenger rail safety applications [1]. The H3-RS is a modification of the standard Hybrid-III 50th percentile male (H3-50M) ATD with additional features in the chest and abdomen to increase its biofidelity and eight sensors to measure deflection. The H3-RS features bilateral (left and right) deflection sensors in the upper and lower chest and in the upper and lower abdomen; whereas, the standard H3-50M only features a single unilateral (center) deflection sensor in the chest with no deflection sensors located in the abdomen. Additional H3-RS research was performed by the Volpe National Transportation Systems Center (Volpe Center) under the direction of the U.S. Department of Transportation, Federal Railroad Administration (FRA) Office of Research, Development, and Technology. The Volpe Center contracted with TRL to conduct a series of dynamic pendulum impact tests [2]. The goal of testing the abdomen response of the H3-RS ATD was to develop data to refine an abdomen design that produces biofidelic and repeatable results under various impact conditions with respect to impactor geometry, vertical impact height, and velocity. In this study, the abdominal response of the H3-RS finite element (FE) model that TRL developed is validated using the results from pendulum impact tests [2]. Results from the pendulum impact tests and corresponding H3-RS FE simulations are compared using the longitudinal relative deflection measurements from the internal sensors in the chest and abdomen as well as the longitudinal accelerometer readings from the impactor. The abdominal response of the H3-RS FE model correlated well with the physical ATD as the impactor geometry, vertical impact height, and velocity were changed. There were limitations with lumbar positioning of the H3-RS FE model as well as the material definition for the relaxation rate of the foam in the abdomen that can be improved in future work. The main goal of validating the abdominal response of the dummy model is to enable its use in assessing injury potential in dynamic sled testing of crashworthy workstation tables, the results of which are presented in a companion paper [3]. The authors used the model of the H3-RS ATD to study the 8G sled test specified in the American Public Transportation Association (APTA) workstation table safety standard [4]. The 8G sled test is intended to simulate the longitudinal crash accleration in a severe train-to-train collision involving U.S. passenger equipment. Analyses of the dynamic sled test are useful for studying the sensitivity of the sled test to factors such as table height, table force-crush behavior, seat pitch, etc., which help to inform discussions on revisions to the test requirements eventually leading to safer seating environments for passengers.

Multidirection Validation of a Finite Element 50th Percentile Male Hybrid III Anthropomorphic Test Device for Spaceflight Applications

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Derek A. Jones ◽  
James P. Gaewsky ◽  
Mona Saffarzadeh ◽  
Jacob B. Putnam ◽  
Ashley A. Weaver ◽  
...  
Keyword(s):  
Finite Element ◽  
Injury Risk ◽  
Fe Model ◽  
Fe Modeling ◽  
Test Device ◽  
Qualitative And Quantitative ◽  
Hybrid Iii ◽  
Physical Tests ◽  
Quantitative Results ◽  
Male Hybrid

The use of anthropomorphic test devices (ATDs) for calculating injury risk of occupants in spaceflight scenarios is crucial for ensuring the safety of crewmembers. Finite element (FE) modeling of ATDs reduces cost and time in the design process. The objective of this study was to validate a Hybrid III ATD FE model using a multidirection test matrix for future spaceflight configurations. Twenty-five Hybrid III physical tests were simulated using a 50th percentile male Hybrid III FE model. The sled acceleration pulses were approximately half-sine shaped, and can be described as a combination of peak acceleration and time to reach peak (rise time). The range of peak accelerations was 10–20 G, and the rise times were 30–110 ms. Test directions were frontal (−GX), rear (GX), vertical (GZ), and lateral (GY). Simulation responses were compared to physical tests using the correlation and analysis (CORA) method. Correlations were very good to excellent and the order of best average response by direction was −GX (0.916±0.054), GZ (0.841±0.117), GX (0.792±0.145), and finally GY (0.775±0.078). Qualitative and quantitative results demonstrated the model replicated the physical ATD well and can be used for future spaceflight configuration modeling and simulation.

Crashworthiness Performance of Space Frame Aluminum Structure in NCAP’s 35 MPH Full Frontal

1999 ◽  
Author(s):  
Mohamed Ridha Baccouche ◽  
Hikmat F. Mahmood ◽  
Arkalgud K. Shivakumar ◽  
Saad A. Jawad
Keyword(s):  
Finite Element ◽  
Rigid Body ◽  
Mass Model ◽  
Space Frame ◽  
Nonlinear Beam ◽  
Rigid Body Dynamic ◽  
Sled Test ◽  
Front End ◽  
Vehicle Component ◽  
Energy Absorbing

Abstract The quest for lighter crash energy absorbing automotive structures has increased the use, parallel with other materials, of the 5xxx sheet and 6xxx extruded aluminum structures. These aluminum structures, when properly designed and joined, are able to demonstrate a very high crash energy absorbing capability. This paper summarizes the CAE and development work performed in the design of the front end structure of a four door C-class space frame aluminum vehicle. Component and system CAE modeling of the front end were conducted under NCAP’s 35 mph full frontal impact using rigid body dynamic, nonlinear beam finite element and stability codes. Component loads versus crash distances and system deceleration versus time responses were computed. A 3D spring mass model was built for the front end structure using the rigid body and finite element code MADYMO. Spring characteristics for each component, derived from test data and component CAE models, were input into the MADYMO model. The deceleration-time response generated by the MADYMO model was used as input for the sled testing. The effects of four parameters were studied and discussed in this paper. These parameters are the steering column angle, IP, Pyro Buckle Pretensioner and airbag vent size. Dummy HIC; chest deceleration; neck shear, tension, compression, flexion and extension; femur load, pelvis acceleration and displacement; retractor load; shoulder belt load; lap belt load and other injury numbers, measured from sled test, are summarized and discussed in this paper.

Development of Performance Requirements for a Rail Passenger Workstation Table Safety Standard

2010 ◽  
Author(s):  
Michelle Muhlanger ◽  
Daniel Parent ◽  
Kristine Severson ◽  
Benjamin Perlman
Keyword(s):  
United States ◽  
Public Transportation ◽  
Injury Risk ◽  
Dynamic Models ◽  
The United States ◽  
Transportation Systems ◽  
Initial Stiffness ◽  
Safety Standard ◽  
Sled Test ◽  
Draft Standard

The American Public Transportation Association’s (APTA) Construction and Structural committee, a railroad industry group, with the support of the Federal Railroad Administration (FRA) and the John A. Volpe National Transportation Systems Center (Volpe Center), is creating an industry safety standard for an energy absorbing table. Workstation tables in passenger trains are an increasingly popular seating configuration both in the United States and abroad. Although a well-attached table can provide convenience and compartmentalization for the occupant, there is a risk of abdominal injury during a rail accident. In Fact, there have been several accidents in the United States in which impacts with workstation tables have severely or fatally injured occupants. In 2006, in response to these injuries, an FRA sponsored program developed a prototype table that distributed load over a wider area of the abdomen and absorbed energy during a collision. This table design was tested with specialized anthropomorphic test devices (ATDs) instrumented to measure abdominal impact response and was shown to decrease injury risk compared to a baseline table design. Building on the knowledge gained in the development of the prototype table, the proposed standard requires force to the abdomen be limited while energy is absorbed by the table. Since manufacturers do not have access specialized ATDs, researchers proposed a two part testing requirement. The first part is a quasi-static test which measures the energy absorption capacity of the table with a maximum force level determined from testing with specialized abdominal ATDs. The second part is a sled test with a standard Hybrid III 50th percentile (HIII) ATD to assess compliance with occupant protection standards of compartmentalization and ATD injury assessment reference values (IARVs). This paper discusses the research performed to develop the performance requirement in the draft standard. Current injury measures, originally developed for the automotive industry, were examined to assess their applicability to workstation table impacts. Multiple Mathematical Dynamic Models (MADYMO) model simulations show the estimated injuries during a simulated sled test scenario. Several force-crush parameters were examined, including the initial stiffness of the force-crush curve, the plateau force and the target energy absorbed by the table, to determined the force-crush design characteristics of a table that are likely to reduce injury risk. The results of this study, combined with testing of the current prototype table described in a companion paper [1], led to a draft standard that will greatly improve the safety of workstation tables in passenger rail cars.

Structural Design Optimization of Side/Rear Impact Guards Using a Coupled Genetic Algorithm Finite Element Method

2004 ◽  
Author(s):  
De-Shin Liu ◽  
Nan-Chun Lin ◽  
Chao-Chin Huang ◽  
Yin-Lee Meng
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Optimal Design ◽  
Computational Time ◽  
Design Parameters ◽  
Fe Model ◽  
Passenger Cars ◽  
Rear Impact ◽  
Structural Design Optimization ◽  
Energy Absorbing

Underride protective structure can reduce serious injures when passenger cars collide with the rear end or side of the heavy vehicle. This paper describes the use of Genetic Algorithm (GA) coupled with a dynamic, inelastic and large deformation finite element (FE) code LS-DYNA to search optimal design of the Side/Rear impact guards. In order to verify the accuracy of the FE model, the simulation results were compared with real experiments follow with the regulation ECE R73. The validated FE model then used to study the optimal design base on under running distance and total amount of energy absorbing capacity. The results from this study shown that this newly developed method not only can found multi-objective design parameters but also can reduce computational time significantly.

Head and Neck Response of an Active Human Body Model and Finite Element Anthropometric Test Device During a Linear Impactor Helmet Test

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
David A. Bruneau ◽  
Duane S. Cronin
Keyword(s):  
Finite Element ◽  
Head And Neck ◽  
Muscle Activation ◽  
Fe Model ◽  
Human Body Model ◽  
Neck Stiffness ◽  
Body Model ◽  
Injury Criteria ◽  
Hybrid Iii ◽  
Primary Impact

Abstract It has been proposed that neck muscle activation may play a role in head response resulting from impacts in American Football. The importance of neck stiffness and active musculature in the standard linear impactor helmet test was assessed using a detailed head and neck finite element (FE) model from a current human body model (HBM) compared to a validated hybrid III head and neck FE model. The models were assessed for bare-head and helmeted impacts at three speeds (5.5, 7.4, and 9.3 m/s) and three impact orientations. The HBM head and neck was assessed without muscle activation and with a high level of muscle activation representing a braced condition. The HBM and hybrid III had an average cross-correlation rating of 0.89 for acceleration in the primary impact direction, indicating excellent correspondence regardless of muscle activation. Differences were identified in the axial head acceleration, attributed to axial neck stiffness (correlation rating of 0.45), but these differences did not have a large effect on the overall head response using existing head response metrics (head injury criteria, brain injury criteria, and head impact power). Although responses that develop over longer durations following the impact differed slightly, such as the moment at the base of the neck, this occurred later in time, and therefore, did not considerably affect the short-term head kinematics in the primary impact direction. Though muscle activation did not play a strong role in the head response for the test configurations considered, muscle activation may play a role in longer duration events.

scholarly journals Influence of Grains Shape Irregularity in Porous Ceramics—Numerical Study

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1944
Author(s):  
Danuta Miedzińska
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Computer Code ◽  
Porous Ceramics ◽  
Ceramic Foam ◽  
Fe Model ◽  
Strength Behavior ◽  
Absorbing Material ◽  
Shape Irregularity ◽  
Energy Absorbing

The presented study deals with the analysis of the stochastic geometry of grains on ceramic foam strength behavior. A microstructural finite element (FE) model of a grainy structure of such a material was developed and stochastic changes to the grain geometry (initially of a regular cubic shape) were introduced. The numerical compression test of a series of finite element models was carried out with the use of LS Dyna computer code. To consider the ceramic specific behavior, the Johnson Holmquist constitutive model was implemented with parameters for alumina. The influence of the stochastic irregularities on the ceramic foam strength was observed—the geometry changes caused an increase in the maximum stress, which could be the basis for the indication that the production of the energy absorbing material should be based on mostly irregular grains.

Subject-Specific Finite Element Models of the Tibia With Realistic Boundary Conditions Predict Bending Deformations Consistent With In Vivo Measurement

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Ifaz T. Haider ◽  
Michael Baggaley ◽  
W. Brent Edwards
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Internal Rotation ◽  
Stress Fracture ◽  
Contact Forces ◽  
Female Participant ◽  
Fe Model ◽  
In Vivo Measurements ◽  
Subject Specific

Abstract Understanding the structural response of bone during locomotion may help understand the etiology of stress fracture. This can be done in a subject-specific manner using finite element (FE) modeling, but care is needed to ensure that modeling assumptions reflect the in vivo environment. Here, we explored the influence of loading and boundary conditions (BC), and compared predictions to previous in vivo measurements. Data were collected from a female participant who walked/ran on an instrumented treadmill while motion data were captured. Inverse dynamics of the leg (foot, shank, and thigh segments) was combined with a musculoskeletal (MSK) model to estimate muscle and joint contact forces. These forces were applied to an FE model of the tibia, generated from computed tomography (CT). Eight conditions varying loading/BCs were investigated. We found that modeling the fibula was necessary to predict realistic tibia bending. Applying joint moments from the MSK model to the FE model was also needed to predict torsional deformation. During walking, the most complex model predicted deformation of 0.5 deg posterior, 0.8 deg medial, and 1.4 deg internal rotation, comparable to in vivo measurements of 0.5–1 deg, 0.15–0.7 deg, and 0.75–2.2 deg, respectively. During running, predicted deformations of 0.3 deg posterior, 0.3 deg medial, and 0.5 deg internal rotation somewhat underestimated in vivo measures of 0.85–1.9 deg, 0.3–0.9 deg, 0.65–1.72 deg, respectively. Overall, these models may be sufficiently realistic to be used in future investigations of tibial stress fracture.

Improve Lower Leg Impact Performance Considering Pedestrian Protection

2011 ◽  
Vol 109 ◽  
pp. 70-74
Author(s):  
Jin Hua Chen ◽  
Xiang Dong Huang
Keyword(s):  
Finite Element ◽  
Lower Leg ◽  
Fe Model ◽  
Test Results ◽  
Pedestrian Protection ◽  
Impact Performance ◽  
Front Structure ◽  
Energy Absorbing

To improve the lower leg impact performance of the vehicle bumper in the collision of vehicle to pedestrian, the finite element (FE) model of a vehicle front structure was developed, and correlated with the test results. The lower legform impactor FE model was used to investigate the performance of the vehicle bumper at different structure conditions. It was finally determined that vehicle to lower legform impact performance can be improved by reducing the energy absorbing foam stiffness and modifying the bumper bracket structure to enlarge the collapse space.

Enhancement of Vehicle/Roadside Hardware Crash: Dynamic Response of Child Occupant Involved in Vehicle/Pole Impact

2011 ◽  
Author(s):  
Ahmed Elmarakbi ◽  
Vid Krznaric ◽  
Khaled Sennah ◽  
William Altenhof ◽  
Michael Chapman
Keyword(s):  
Finite Element ◽  
Deformable Objects ◽  
Child Injuries ◽  
Soil Systems ◽  
Vehicle Impact ◽  
Hybrid Iii ◽  
Protection Devices ◽  
Energy Absorbing ◽  
Roadside Hardware ◽  
Child Occupant

This paper focuses on minimizing child injuries experienced during frontal vehicle-to-pole collisions by improving on the safety and energy absorption of existing traffic pole structures. A finite element computer model, using LS-DYNA software, is used to simulate crash events in order to determine the influence of pole structural and material characteristics on the injury parameters of a hybrid III 3-year-old child dummy occupant. Different pole support systems and laminar traffic poles of different materials are investigated in this paper. It is concluded that the anchored base support and the embedded pole in soil systems provide desirable crashworthy results, thus reducing fatalities and injuries resulting from vehicle impact. It is also recommended to mandate traffic protection devices in all areas with poor energy absorbing characteristics that resemble non-deformable objects.

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