Computer Simulation of Occupant Neck Response to Airbag Deployment in Frontal Impacts

1992 ◽  
Vol 114 (3) ◽  
pp. 327-331 ◽  
Author(s):  
K. H. Yang ◽  
B. K. Latouf ◽  
A. I. King
Keyword(s):  
Steering Wheel ◽  
Base Line ◽  
Impact Model ◽  
Test Results ◽  
Head Acceleration ◽  
Joint Torques ◽  
Sled Test ◽  
Frontal Impacts ◽  
Model Predictions ◽  
Head And Neck Injury

A mathematical simulation was performed to study the potential of head and neck injury to an unbelted driver restrained by an airbag. The baseline study represented a 50th percentile male dummy driving in a compact car with the steering wheel perpendicular to the floor. The vehicle was moving at 48 km/hour at the time of impact. Model predictions were compared with sled test results. The data agreed reasonably well. A parametric study was performed to study the effect of changing the steering wheel angle and the size of the airbag. It was found that when the standard 20 degrees angle steering wheel was used, neck joint torques were decreased by 22 percent while the resultant head acceleration increased 41 percent from the base line study. When the vertical dimension of the airbag was reduced by 10 percent, neck joint torques were increased by 14 percent, while head acceleration showed a slight decrease of 9 percent.

Methodology Development for Simulating Full Frontal and Offset Frontal Impacts Using Full Vehicle MADYMO Models

1999 ◽  
Author(s):  
Bala Deshpande ◽  
Gunasekar TJ ◽  
Russell Morris ◽  
Sudhanshu Parida ◽  
Mostafa Rashidy ◽  
...  
Keyword(s):  
Rigid Body ◽  
Joint Stiffness ◽  
Side Impact ◽  
Computational Time ◽  
Test Results ◽  
Vehicle Interior ◽  
Significant Saving ◽  
Methodology Development ◽  
Full Vehicle ◽  
Frontal Impacts

Abstract MADYMO articulated full vehicle models of the 1992 Ford Taurus, 1995 Chevrolet Lumina and the 1994 Dodge Intrepid for frontal and side impact modes have been developed and validated against test data. MADYMO (Mathematical Dynamic Model) is typically used to model occupants in the environment of the vehicle interior and thus finds application mainly in assessing occupant injuries. In this study however, MADYMO has been employed not only to model the occupants but also to represent the major load bearing structures in the vehicles. Input for the MADYMO models consisting of rigid body joint stiffness was obtained from corresponding full vehicle Finite Element (FE) models. Model validation was done by comparing the vehicle and dummy numbers with the New Car Assessment Program (NCAP) test results. Models correlated very well with both test and FE data. This modeling approach demonstrates the utility of rigid body based full car models for crashworthiness analysis. Such models result in significant saving in computational time and resources. In this paper, we describe the simulation of two different crash modes: full frontal and offset frontal impacts using the full vehicle MADYMO models. These simulations were validated with the corresponding test results in full frontal mode and IIHS offset mode. The models are useful for simulating a variety of impact situations, for example, with different occupant sizes, occupant positions, impact velocities, and in car to car impacts for performing compatibility studies.

Compliant Pantographs via the Pseudo-Rigid-Body Model

1998 ◽  
Author(s):  
Andrew J. Nielson ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Test Results ◽  
Rigid Link ◽  
Body Model ◽  
Design Flexibility ◽  
Model Predictions ◽  
Rigid Body Model ◽  
Classical Mechanism

Abstract This paper uses a familiar classical mechanism, the pantograph, to demonstrate the utility of the pseudo-rigid-body model in the design of compliant mechanisms to replace rigid-link mechanisms, and to illustrate the advantages and limitations of the resulting compliant mechanisms. To demonstrate the increase in design flexibility, three different compliant mechanism configurations were developed for a single corresponding rigid-link mechanism. The rigid-link pantograph consisted of six links and seven joints, while the corresponding compliant mechanisms had no more than two links and three joints (a reduction of at least four links and four joints). A fourth compliant pantograph, corresponding to a rhomboid pantograph, was also designed and tested. The test results showed that the pseudo-rigid-body model predictions were accurate over a large range, and the mechanisms had displacement characteristics of rigid-link mechanisms in that range. The limitations of the compliant mechanisms included reduced range compared to their rigid-link counterparts. Also, the force-deflection characteristics were predicted by the pseudo-rigid-body model, but they did not resemble those for a rigid-link pantograph because of the energy storage in the flexible segments.

The Effect of Vehicles Steering Tilt Angle Impact Human Thorax

2013 ◽  
Vol 397-400 ◽  
pp. 585-588
Author(s):  
Zhi Hua Cai ◽  
Feng Chong Lan ◽  
Ji Qing Chen
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Tilt Angle ◽  
Head Injuries ◽  
Steering Wheel ◽  
Human Body Model ◽  
Body Model ◽  
Frontal Impacts ◽  
Wheel Rim ◽  
Human Thorax

Thorax injuries are common in vehicular accidents, second only to head injuries. Unbelted drivers of vehicles are more likely to suffer thorax injuries from steering wheel contact in frontal impacts. The objective of this study is to investigate the effects the steering wheel tilt angle (0, 20, 40, and 60) impact to the thorax of human body model with respect to thorax deflection and steering wheel rim contact interaction. To understanding of the human thorax sensitivity to steering wheel tilt angle on the force and deflection response using finite element simulations. It was found that the thorax response is sensitive to changes in steering wheel tilt angle. The contact force, Sternal displacement were the key parameters to be observed and compared. The results show that the contact force increased when the steering wheel tilt angle was bigger, the response was quicker. Low steering wheel tilt resulted in greater deformation. The greater the contact force, the deformation of the sternum but reduced when thorax impact the steering wheel, According to ECE R12 steering wheel regulation ,use force regulations to assessment the injury of the thorax is not accurate enough when human thorax impact the steering wheel.

scholarly journals UNDERWATER MOUND FOR THE PROTECTION OF DURBAN'S BEACHES

1970 ◽  
Vol 1 (12) ◽  
pp. 62 ◽  
Author(s):  
J.A. Zwaborn ◽  
G.A.W. Fromme ◽  
J.B. FitzPatrick
Keyword(s):  
Settling Velocity ◽  
Scale Effects ◽  
Similarity Criterion ◽  
Test Results ◽  
Beach Profile ◽  
Reasonable Degree ◽  
Model Predictions ◽  
Profile Changes ◽  
High Degree ◽  
Movable Bed

The construction of an underwater mound of sand for the protection and improvement of Durban's beaches has been recommended on the basis of intensive investigations These investigations included prototype measurements of beach changes as related to recorded sea conditions, basic scaling tests in which these beach changes were reproduced to scale in movable bed models and tests of the proposed underwater mound in models, using different scales in order to eliminate possible scale effects The test results showed that, provided the shear-settling velocity similarity criterion is satisfied, beach changes can be reproduced in a movable bed model to a reasonable degree of accuracy Optimum dimensions for the cross section of the mound were determined on the basis of the criterion for erosive and non-erosive wave conditions which was derived from the prototype beach profile changes and confirmed by model tests The resulting dimensions are a mound of sand about 4 5 km long, about 1 200 m offshore, reaching to 7 3 m below LWOST, with side slopes of 1 in 25 and a crest width of 61 m 3 3 Of the total quantity required (8 000 000 m ) some 2 500 000 m of sand, available from harbour dredging works in Durban Bay, had been dumped by May, 1970 Model predictions on mound stability and beach improvements were confirmed to a high degree of accuracy by the full scale events.

Test Results and Analytical Predictions for Rotor Drop Testing of an AMB Expander/Generator

2006 ◽  
Author(s):  
Lawrence Hawkins ◽  
Alexei Filatov ◽  
Shamim Imani ◽  
Darren Prosser
Keyword(s):  
High Speed ◽  
High Performance ◽  
Time History ◽  
Test Results ◽  
Direct Drive ◽  
Flow Loop ◽  
Low Loss ◽  
Model Predictions ◽  
Full Speed ◽  
Insight Into

A cryogenic gas expander system that incorporates a high performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000 rpm was completed at the system manufacturer’s facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000 rpm. Orbit and time-history data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support and hard stop. Model predictions are discussed relative to the test data.

scholarly journals The Effects of Curtain Airbag on Occupant Kinematics and Injury Index in Rollover Crash

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hongyun Li ◽  
Chengyue Jiang ◽  
Dong Cui ◽  
Shuang Lu
Keyword(s):  
Restraint System ◽  
Head Acceleration ◽  
Physical Test ◽  
Injury Index ◽  
Hybrid Iii ◽  
Protection Area ◽  
Occupant Injuries ◽  
Occupant Kinematics ◽  
Head And Neck Injury ◽  
Rollover Crash

Background. Occupant injuries in rollover crashes are associated with vehicle structural performance, as well as the restraint system design. For a better understanding of the occupant kinematics and injury index in certain rollover crash, it is essential to carry out dynamic vehicle rollover simulation with dummy included. Objective. This study focused on effects of curtain airbag (CAB) parameters on occupant kinematics and injury indexes in a rollover crash. Besides, optimized parameters of the CAB were proposed for the purpose of decreasing the occupant injuries in such rollover scenario. Method and Material. The vehicle motion from the physical test was introduced as the input for the numerical simulation, and the 50% Hybrid III dummy model from the MADYMO database was imported into a simulation model. The restraint system, including a validated CAB module, was introduced for occupant kinematics simulation and injury evaluation. TTF setting, maximum inflator pressure, and protection area of the CAB were analysed. Results. After introducing the curtain airbag, the maximum head acceleration was reduced from 91.60 g to 49.52 g, and the neck Mx and neck Fz were reduced significantly. Among these CAB parameters, the TTF setting had the largest effect on the head acceleration which could reduce 8.6 g furthermore after optimization. The neck Fz was decreased from 3766.48 N to 2571.77 N after optimization of CAB protection area. Conclusions. Avoiding hard contact is critical for the occupant protection in the rollover crashes. The simulation results indicated that occupant kinematics and certain injury indexes were improved with the help of CAB in such rollover scenario. Appropriate TTF setting and inflator selection could benefit occupant kinematics and injury indexes. Besides, it was advised to optimize the curtain airbag thickness around the head contact area to improve head and neck injury indexes.

scholarly journals Plastic anisotropy of soft reconstituted clays

2008 ◽  
Vol 45 (3) ◽  
pp. 314-328 ◽  
Author(s):  
Minna Karstunen ◽  
Mirva Koskinen
Keyword(s):  
Stress Ratio ◽  
Plastic Anisotropy ◽  
Stress Path ◽  
Test Results ◽  
Fabric Anisotropy ◽  
Induced Anisotropy ◽  
Modified Cam Clay ◽  
Model Predictions ◽  
Elastoplastic Constitutive Model ◽  
Cam Clay

The aim of the paper is to extend the experimental validation of the S-CLAY1 model, which is a recently proposed elastoplastic constitutive model that accounts for initial and plastic strain-induced anisotropy. Drained stress path controlled tests were performed on reconstituted samples of four Finnish clays to study the effects of anisotropy in the absence of the complexities of structure present in natural undisturbed clays. Each test involved several loading, unloading, and reloading stages with different values of stress ratio and, hence, induced noticeable changes in the fabric anisotropy. Comparisons between test results and model predictions with the S-CLAY1 model and the modified Cam clay model demonstrate that despite its simplicity, the S-CLAY1 model can provide excellent predictions of the behaviour of unstructured soil.

Simulation of Natural Pisa Clay Using an Enhanced Anisotropic Elastoplastic Bounding Surface Model

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
Jianhong Jiang ◽  
Hoe I. Ling ◽  
Victor N. Kaliakin
Keyword(s):  
Plastic Anisotropy ◽  
Complex Stress ◽  
Surface Model ◽  
Test Results ◽  
Compression Tests ◽  
Bounding Surface ◽  
Proportional Loading ◽  
Model Predictions ◽  
Loading Tests ◽  
Basic Features

The experimental behavior of natural Pisa clay under complex stress paths is simulated by an enhanced anisotropic elastoplastic bounding surface model. In its present application, the model has nine parameters and focuses on the basic features of clay behavior, such as yielding, critical state, overconsolidation and plastic anisotropy. The model is first calibrated against the test results obtained from tri-axial compression tests and subsequently used to predict the behavior of true tri-axial tests. The overall agreement between the model predictions and the experimental data is very good for proportional loading tests in both meridional and deviatoric stress spaces. The result of prediction is also compared with the original simulations that were conducted by an advanced clay model.

scholarly journals Assessment of Nanobag as a New Safety System in the Frontal Sled Test

2021 ◽  
Author(s):  
Jan Špička ◽  
Tomasz Bońkowski ◽  
Luděk Hynčík ◽  
Alojz Hanuliak
Keyword(s):  
Material Model ◽  
Safety System ◽  
Crash Test ◽  
Human Body Model ◽  
Test Scenario ◽  
Sled Test ◽  
Frontal Impacts ◽  
Injury Criteria ◽  
Extended Application ◽  
Safety Systems

Objective: The future mobility challenges leads to considering new safety systems to protect vehicle passengers in non-standard and complex seating configurations. The objective of this study is to assess the performance of a brand new safety system called nanobag and to compare it to the traditional airbag performance in the frontal sled test scenario. Methods: The nanobag technology is assessed in the frontal crash test scenario and compared with the standard airbag by numerical simulation. The previously identified material model is used to assemble the nanobag numerical model. The paper exploits an existing validated human body model to assess the performance of the nanobag safety system. Using both the new nanobag and the standard airbag, the sled test numerical simulations with the variation of human bodies are performed in 30 km/h and 50 km/h frontal impacts. Results: The sled test results for both the nanobag and the standard airbag based on injury criteria shows a good and acceptable performance of the nanobag safety system compared to the traditional airbag. Conclusion: The results show that the nanobag system has its performance compared to the standard airbag, which means that thanks to the design, the nanobag safety system has a high potential and extended application for multi-directional protection against impact.

scholarly journals Prevalence of Extended Spectrum b-Lactamases (ESBL) Producers Among Gram-Negative Bacilli in Wound Infection

2016 ◽  
Vol 15 (1) ◽  
pp. 26-30
Author(s):  
Abu Hena Md Saiful Karim Chowdhury ◽  
Md Anwar Husain ◽  
Nasima Akter ◽  
Khan Mashrequl Alam ◽  
Arup Kanti Dewanjee ◽  
...  
Keyword(s):  
Wound Infection ◽  
Confirmatory Test ◽  
Base Line ◽  
Gram Negative Bacteria ◽  
Test Results ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Extended Spectrum ◽  
Severe Infections ◽  
Esbl Producers

Background: Extended Spectrum b -Lactameses Producing Organisms (ESBLs) are increasing in number and causing more severe infections because of their continuous mutation and multidrug resistance property with limited therapeutic option.Aims and Objectives: Present study was undertaken to detect the prevalence of the ESBLs producing bacteria in wound infection, so as to provide a base line data in treating them & prevent unnecessary use of antibioticsMethods: Isolated gram-negative bacteria initially screened by Minimum Inhibitory Concentration (MIC) ESBLs breakpoints. Then suspected ESBLs producers were confirmed by Phenotypic confirmatory test. Results: 105 (One hundred five) (91.30%) bacterial strains were isolated from 115 samples of wound swab & pus from different patients were studied of which 84(80.00%) were Gram-negative and 21(20.00%) were Gram-positive. Among the isolated Gram-negative bacteria 79(94.05%) were found suspected ESBLs producers of which 54(68.35%) were found as confirmed ESBL producers. The prevalence of ESBLs producing organisms in the present study were found to be 64.29% and Klebsiella spp as most prevalent ESBLs producers.Conclusion: It is essential to report ESBL production along with routine sensitivity reporting, which will help the clinician in prescribing the proper antibiotics.Chatt  Shi Hosp Med Coll J; Vol.15 (1); Jan 2016; Page 26-30

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