An Integrated Modeling Method to Evaluate Fleet Safety Performance of New Vehicle Designs

2013 ◽  
Author(s):  
Randa Radwan Samaha ◽  
Priyaranjan Prasad ◽  
Dhafer Marzougui ◽  
Chongzhen Cui ◽  
Cing-Dao (Steve) Kan ◽  
...  
Keyword(s):  
Finite Element ◽  
Real World ◽  
Injury Risk ◽  
Three Dimensional ◽  
Structural Models ◽  
Passenger Compartment ◽  
Different Types ◽  
Structural Deformations ◽  
Scale Test ◽  
Frontal Crashes

A methodology for Evaluating Fleet, i.e., self and partner, Protection (EFP) of new vehicle designs is developed through a systems modeling approach driven by structural and occupant modeling and real world crash and full scale test data. The EFP methodology consists of a virtual model simulating the real world crash environment (i.e., different types of vehicles, impact velocities, impact directions, impact types, etc.). A concept or new vehicle design could be introduced into this model to evaluate the safety of its occupants and those of other vehicles with which it is involved in crashes. The initial implementation of EFP methodology is to frontal crashes where the modeled crash configurations are derived from a new crash taxonomy based on real world structural engagement. Simulation data to drive the methodology is obtained from finite element structural models of the vehicles. Occupant responses are based on three dimensional articulated rigid body models of the occupant and the passenger compartment. The occupant is restrained by seat belts and airbags and the structural deformations and kinematics of the passenger compartment needed to drive the occupant models are predicted by the finite element structural models. Both the structural and the occupant models are subjected to validation and robustness checks for the modeled crash configurations. The aggregate of injury risk across vehicle classes, impact speeds, occupant sizes, and crash configurations, weighted by relative frequency of the specific event in real world crashes, is used as a measure of overall societal safety. Results from a proof-of-concept application are presented.

Assessment of Acclimation of 5th Percentile Female and 50th Percentile Male Volunteer Kinematics in Low-Speed Frontal and Frontal-Oblique Sled Tests

2021 ◽  
Vol 9 (1) ◽  
pp. 3-103
Author(s):  
Hana Chan ◽  
◽  
Devon Albert ◽  
F Scott Gayzik ◽  
Andrew R Kemper ◽  
...  
Keyword(s):  
Injury Risk ◽  
Three Dimensional ◽  
Small Female ◽  
Low Speed ◽  
Demographic Groups ◽  
Multiple Test ◽  
Test Conditions ◽  
Male Volunteers ◽  
Wide Range ◽  
Frontal Crashes

In order to accurately represent the response of live occupants during pre-crash events and frontal crashes, computational human body models (HBMs) that incorporate active musculature must be validated with appropriate volunteer data that represents a wide range of demographic groups and potential crash conditions. The purpose of this study was to quantify and compare occupant kinematic responses for unaware (relaxed) small female and midsize male volunteers during low-speed frontal and frontal-oblique sled tests across multiple test conditions, while recognizing, assessing, and accounting for potential acclimation effects due to multiple exposures. Six 5th percentile female and six 50th percentile male volunteers were exposed to multiple low-speed frontal and frontal-oblique sled tests on two separate test days. Volunteers experienced one test orientation and two pulse severities (1 g and 2.5 g) on each test day. A Vicon motion capture system was used to quantify the three-dimensional (3D) kinematics of the volunteers. Peak forward excursions of select body locations were compared within a test day and between test days for the same test condition to determine if and how acclimation occurred. Differences between demographic groups were also compared after accounting for any observed acclimation. Acclimation was not observed within a test day but was observed between test days for some demographic groups and some test conditions. In general, head, neck, and shoulder responses were affected, but the elbow, hip, and knee responses were not. Males generally moved farther forward compared to females during the frontal tests, but both groups moved forward similarly during the frontal-oblique tests. Overall, this study provides new female and male biomechanical data that can be used to further develop and validate HBMs that incorporate active musculature in order to better understand and assess occupant response and injury risk in pre-crash events and frontal crashes.

Experimental study on anti-collision device using titanium steel and recycle tires

2021 ◽  
Author(s):  
Ziheng Xin ◽  
Haiying Ma ◽  
Junjie Wang ◽  
Hao Gao ◽  
Yanchen Song
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Test Specimen ◽  
Impact Load ◽  
Finite Element Models ◽  
Strong Impact ◽  
New Device ◽  
Different Types ◽  
Scale Test ◽  
Ship Collision

<p><br clear="none"/></p><p>Anti-collision devices can reduce the damage of bridge columns under ship collision, and a new device is proposed in the paper using a combination of titanium steel and recycle tires. The proposed device effectively improves the performance of buffering energy dissipation and durability under strong impact load. A 0.6 scale test specimen was designed and tested to investigate the behavior of the device under impact load; finite element models were conducted to analyze and compare with the experimental results. The performances of different types of the anti-collision device are compared, and the failure mechanism is studied.</p>

scholarly journals Finite-element analysis of microwave scattering from a three-dimensional human head model for brain stroke detection

2018 ◽  
Vol 5 (7) ◽  
pp. 180319
Author(s):  
Awais Munawar Qureshi ◽  
Zartasha Mustansar ◽  
Samah Mustafa
Keyword(s):  
Finite Element ◽  
Dielectric Properties ◽  
Electric Field ◽  
Three Dimensional ◽  
Human Head ◽  
Head Model ◽  
Different Types ◽  
Brain Stroke ◽  
Human Head Model ◽  
Brain Stroke Detection

In this paper, a detailed analysis of microwave (MW) scattering from a three-dimensional (3D) anthropomorphic human head model is presented. It is the first time that the finite-element method (FEM) has been deployed to study the MW scattering phenomenon of a 3D realistic head model for brain stroke detection. A major contribution of this paper is to add anatomically more realistic details to the human head model compared with the literature available to date. Using the MRI database, a 3D numerical head model was developed and segmented into 21 different types through a novel tissue-mapping scheme and a mixed-model approach. The heterogeneous and frequency-dispersive dielectric properties were assigned to brain tissues using the same mapping technique. To mimic the simulation set-up, an eight-elements antenna array around the head model was designed using dipole antennae. Two types of brain stroke (haemorrhagic and ischaemic) at various locations inside the head model were then analysed for possible detection and classification. The transmitted and backscattered signals were calculated by finding out the solution of the Helmholtz wave equation in the frequency domain using the FEM. FE mesh convergence analysis for electric field values and comparison between different types of iterative solver were also performed to obtain error-free results in minimal computational time. At the end, specific absorption rate analysis was conducted to examine the ionization effects of MW signals to a 3D human head model. Through computer simulations, it is foreseen that MW imaging may efficiently be exploited to locate and differentiate two types of brain stroke by detecting abnormal tissues’ dielectric properties. A significant contrast between electric field values of the normal and stroke-affected brain tissues was observed at the stroke location. This is a step towards generating MW scattering information for the development of an efficient image reconstruction algorithm.

Finite Element Prediction of Proximal Femoral Fracture Patterns Under Different Loads

2005 ◽  
Vol 127 (1) ◽  
pp. 9-14 ◽  
Author(s):  
M. J. Go´mez-Benito ◽  
J. M. Garcı´a-Aznar ◽  
M. Doblare´
Keyword(s):  
Finite Element ◽  
Proximal Femur ◽  
Fracture Criterion ◽  
Three Dimensional ◽  
Proximal Femoral Fracture ◽  
Tissue Microstructure ◽  
Different Types ◽  
Anisotropic Elastic ◽  
Type Of Fracture ◽  
Finite Element Prediction

The main purpose of this work is to discuss the ability of finite element analyses, together with an appropriate anisotropic fracture criterion, to predict the ultimate load and type of fracture in bones and more specifically in the proximal femur. We show here that the use of a three-dimensional anisotropic criterion provides better results than other well-known isotropic criteria. The criterion parameters and the anisotropic elastic properties were defined in terms of the bone tissue microstructure, quantified by the apparent density and the so-called “fabric tensor”, whose spatial distributions were obtained by means of an anisotropic remodeling model able to capture the main features of the internal structure of long bones. In order to check the validity of the results obtained, they have been compared with those of an experimental work that analyzes different types of fractures induced in the proximal femur by a static overload.

UNCERTAINTIES OF IMPACT CONFIGURATION FOR NUMERICAL REPLICATIONS OF REAL-WORLD TRAUMA: A FE ANALYSIS

2016 ◽  
Vol 16 (08) ◽  
pp. 1640018 ◽  
Author(s):  
MICHÈLE BODO ◽  
SÉBASTIEN ROTH
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Real World ◽  
Injury Risk ◽  
Body Position ◽  
Free Fall ◽  
Experimental Tests ◽  
Element Model ◽  
The Body ◽  
Thoracic Injury

This study deals with free fall accident analysis involving adults, and their numerical replications using a finite element model of the human thorax. The main purpose is to determine the role of body position at impact in the thorax injury risk appearance. For this study, cases of real-world free-fall provided by an emergency department were selected and investigated. These cases involved both male and female with an age range of 20 to 63 years, who sustained accidental free-fall with both injured and uninjured cases. The examination of the patients' medical record provided helpful information to accurately perform numerical replications with the finite element model HUByx (Hermaphrodite Universal Biomechanical yx model) which was already validated for various experimental tests in the field of automobile, ballistic impacts and blast. The results of simulations at different impact location allowed highlighting the crucial influence of the body orientation in the risk of thoracic injury occurrence.

Plastic Analysis for Cylindrical Vessels Under In-Plane Moment on the Nozzle

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
B. H. Wu ◽  
Z. F. Sang ◽  
G. E. O. Widera
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Limit Load ◽  
Cylindrical Vessel ◽  
Plastic Limit ◽  
Element Analysis ◽  
Test Models ◽  
Scale Test ◽  
Plastic Limit Load

The objective of this paper is to determine the plastic limit moment for cylindrical vessels with a nozzle under in-plane moment loading. Three full scale test models with different d/D ratios were fabricated for the experiment. A three-dimensional nonlinear finite element analysis was also performed. The plastic limit moment of the cylindrical vessel-nozzle connections was determined approximately by the twice-elastic-slope criterion. The results indicate that the plastic limit moments obtained by the experiment and finite element analysis are in good agreement. On the basis of the above results, a parametric analysis of the plastic limit moment for cylindrical vessels under in-plane moment on the nozzle was carried out, and an empirical formula is proposed. The results can serve as a supplement to the available data of plastic limit load for cylindrical vessel-nozzle connection structures under external load.

Restraint Systems in Tactical Vehicles: Uncertainty Study Involving Airbags, Seatbelts and Military Gear

2017 ◽  
Author(s):  
Dorin Drignei ◽  
Zissimos P. Mourelatos ◽  
Ervisa Zhamo ◽  
Jingwen Hu ◽  
Cong Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Body Size ◽  
Injury Risk ◽  
Finite Element Models ◽  
Risk Distribution ◽  
Frontal Crashes ◽  
Safety Features ◽  
The Impact

Adding advanced safety features (e.g. airbags) to restraint systems in tactical vehicles could decrease the injury risk of their occupants. The impact of frontal crashes on the occupants has been assessed recently through experimental data and finite element models. However, the number of such experiments is relatively small due to high cost. In this paper, we conduct an uncertainty study to infer the advantage of including advanced safety features, if a larger number of experiments were possible. We introduce the concept of group injury risk distribution that allows us to quantify under uncertainty the injury risk associated with advanced safety features, while averaging out the effect of uncontrollable factors such as body size. Statistically, the group injury risk distribution is a mixture of individual injury risk distributions of design conditions in the group. We infer that advanced safety features reduce the injury risk by at least two thirds in frontal crashes.

Restraint Systems in Tactical Vehicles: Uncertainty Study Involving Airbags, Seatbelts, and Military Gear

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Dorin Drignei ◽  
Zissimos P. Mourelatos ◽  
Ervisa Zhamo ◽  
Jingwen Hu ◽  
Cong Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Body Size ◽  
Injury Risk ◽  
Risk Distribution ◽  
Frontal Crashes ◽  
Safety Features ◽  
The Impact

Adding advanced safety features (e.g., airbags) to restraint systems in tactical vehicles could decrease the injury risk of their occupants. The impact of frontal crashes on the occupants has been assessed recently through experimental data and finite element (FE) models. However, the number of such experiments is relatively small due to high cost. In this paper, we conduct an uncertainty study to infer the advantage of including advanced safety features, if a larger number of experiments were possible. We introduce the concept of group injury risk distribution that allows us to quantify under uncertainty the injury risk associated with advanced safety features, while averaging out the effect of uncontrollable factors such as body size. Statistically, the group injury risk distribution is a mixture of individual injury risk distributions of design conditions in the group. We infer that advanced safety features have the potential to reduce substantially injury risk in frontal crashes.

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