Validation of a Finite Element 50th Percentile THOR Anthropomorphic Test Device in Multiple Sled Test Configurations

2018 ◽  
Author(s):  
Kyle P. McNamara ◽  
Derek A. Jones ◽  
James P. Gaewsky ◽  
Jacob B. Putnam ◽  
Jeffrey T. Somers ◽  
...  
Keyword(s):  
Finite Element ◽  
Test Device ◽  
Sled Test

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.

Finite Element Dynamic Analysis of a Railway Seat Under Longitudinal Impact Condition

2011 ◽  
Author(s):  
Francesco Caputo ◽  
Giuseppe Lamanna ◽  
Alessandro Soprano
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Seat Belt ◽  
Element Model ◽  
Railway Vehicle ◽  
Longitudinal Impact ◽  
Structural Behaviour ◽  
Structural Dynamic ◽  
Sled Test ◽  
Seat Frame

For a railway vehicle, the structural integrity of the seat frame and of its connection to that of the coach is a very important aspect of the design phase addressed to the improvement of the passive safety performances, at most because the analysis of the accidents occurred in recent years shows that secondary impacts against vehicle interiors remain one of the main causes of injury. All regulations which apply to this task start from the assumption that whatever happens to the vehicle the seat must remain connected to the vehicle frame, as well as the different parts to each other. Numerical evaluations are obviously necessary to match with this design requirement; it would be desirable to apply multi-body (MB) codes to this task, as they are really fast, but unfortunately they can’t provide detailed results for what concerns the structural behaviour of the involved seat and vehicle components. For this reason, in the present work a full finite element model of a sled-test, including a FE dummy, has been developed, analysed and validated by comparison with the available experimental results; it has been also showed how this kind of numerical simulation is suited and necessary to evaluate the structural behaviour of the structural components of the seat frame. In the context of the presented study the MADYMO® code has been adopted to perform the preliminary MB analyses necessary to calibrate and evaluate the relevant parameters of dummy-seat contact surfaces and of seat-belt stiffness, while LS DYNA® code has been used for the structural dynamic FE analyses.

Evaluation of Dynamic Performance of Aircraft Seats for Larger Passenger Population Using Finite Element Analysis

2012 ◽  
Author(s):  
Prasannakumar S. Bhonge ◽  
Rasoul Moradi ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Integrity ◽  
Dynamic Testing ◽  
Dynamic Performance ◽  
General Aviation ◽  
Element Analysis ◽  
Sled Test ◽  
Passenger Seat ◽  
Test Parameters

Dynamic aircraft seat regulations are identified in the Code of Federal Regulations (CFR), 14 CFR Parts § XX.562 for crashworthy evaluation of a seat in dynamic crash environment. The regulations specify full-scale dynamic testing on production seats. The dynamic tests are designed to demonstrate the structural integrity of the seat to withstand an emergency landing event and occupant safety. These tests are carried out on a 50th percentile Hybrid II Anthropomorphic Test Device (ATD) representing average 50 percent of human population. In this study, the dynamic performance of seats are evaluated for larger passenger population for both transport and general aviation seats. For this, Finite Element Analysis (FEA) of an aircraft seat model is analyzed by utilizing a 50th percentile e-ATD and validated with a 50th percentile ATD sled test results. Then the effect of a 95th percentile standard ATD in an aircraft passenger seat is investigated using FEA. Comparison of the 50th percentile and the 95th percentile electronic ATD models (e-ATDs) is carried out on the test parameters. This includes the restraint loads, the floor reactions and the head paths. Based on the comparison it is concluded that the seat loads go up in the range of 20 to 30% if designed for larger passenger population.

Computational Modeling and Performance Evaluation of a DAX-Foam Aircraft Seat Cushion Utilizing High Loading Rate Dynamic Characteristics

2010 ◽  
Author(s):  
Prasannakumar S. Bhonge ◽  
Chandrashekhar K. Thorbole ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Loading Rate ◽  
Full Scale ◽  
High Loading ◽  
Finite Element Models ◽  
Test Results ◽  
Sled Test ◽  
Seat Cushion ◽  
High Loading Rate ◽  
The Cost

The aircraft seat dynamic performance standards as per CFR 14 FAR Part 23, and 25 requires the seat to demonstrate crashworthy performance as evaluated using two tests namely Test-I and Test-II conditions. Test-I dynamic test includes a combined vertical and longitudinal dynamic load to demonstrate the compliance of lumbar load requirement for a Hybrid II or an FAA Hybrid III Anthropomorphic Test Device (ATD). The purpose of this test is to evaluate the means by which the lumbar spine of the occupant in an impact landing can be reduced. This test requirement is mandatory with every change in the seat design or the cushion geometry. Experimental full-scale crash testing is expensive and time-consuming event when required to demonstrate the compliance issue. A validated computational technique in contrast provides an opportunity for the cost effective and fast certification process. This study mainly focuses on the characteristics of DAX foams, typically used as aircraft seat cushions, as obtained both at quasi-static loading rate and at high loading rate. Nonlinear finite element models of the DAX foam are developed based on the experimental test data from laboratory test results conducted at different loading rates. These cushion models are validated against sled test results to demonstrate the validity of the finite element models. The results are compared for these computational sled test simulations with each seat cushion as obtained using quasi-static and high-loading rate characteristics. The result demonstrates a better correlation of the simulation data with the full scale crash test data for the DAX foam when high loading rate data is utilized instead of quasi-static data in the dynamic finite element models. These models can be utilized in the initial design of the aircraft seats, and thus reducing the cost and time of a full-scale sled test program.

scholarly journals Failure analysis of a frangible composite cover: A transient-dynamics study

2016 ◽  
Vol 51 (18) ◽  
pp. 2607-2617
Author(s):  
Deng’an Cai ◽  
Guangming Zhou ◽  
Yuan Qian ◽  
Vadim V Silberschmidt
Keyword(s):  
Finite Element ◽  
Failure Analysis ◽  
Failure Criterion ◽  
Element Model ◽  
Transient Dynamics ◽  
Dynamics Model ◽  
Test Device ◽  
Weak Zone ◽  
Failure Pressure ◽  
Model Failure

A transient-dynamics model based on the approximate Riemann algorithm is proposed for the failure analysis of a frangible composite canister cover. The frangible cover, manufactured with a traditional manual lay-up method, is designed to conduct a simulated missile launch test using a specially developed test device. Deformation of the cover’s centre is determined using a transient-dynamics finite element model; failure pressure for the frangible cover is obtained based on a failure criterion and compared with simulated experimental results. Weak-zone position of the frangible cover has a significant effect on failure pressure compared to that of deformation of the cover’s centre. With the same structure of the weak-zone, an increase in its height can first raise and then reduce the level of failure pressure of the frangible cover. Close agreements between the experimental and numerical results are observed.

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