Marseille, France
Marseille, France

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Montava M.,Aix - Marseille University | Deveze A.,University Hospital Nord | Arnoux P.-J.,Aix - Marseille University | Bidal S.,Altair Development France | And 2 more authors.
Otology and Neurotology | Year: 2012

OBJECTIVE: The temporal bone shields sensorineural, nervous, and vascular structures explaining the potential severity and complications of trauma related to road and sport accidents. So far, no clear data are available on the exact mechanisms involved for fracture processes. Modelization of structures helps to answer these concerns. Our objective was to design a finite element model of the petrous bone structure to modelize temporal bone fracture propagation in a scenario of lateral impact. MATERIALS AND METHODS: A finite element model of the petrous bone structure was designed based on computed tomography data. A 7-m/s lateral impact was simulated to reproduce a typical lateral trauma. Results of model analysis was based on force recorded, stress level on bone structure up to induce a solution of continuity of the bony structure. RESULTS: Model simulation showed that bone fractures follow the main axes of the petrous bone and occured in a 2-step process: first, a crush, and second, a massive fissuration of the petrous bone. The lines of fracture obtained by simulation of a lateral impact converge toward the middle ear region. This longitudinal fracture is located at the mastoid-petrous pyramid junction. DISCUSSION: Using this model, it was possible to map petrous bone fractures including fracture chronology and areas of fusion of the middle ear region. This technique may represent a first step to investigate the pathophysiology of the petrous bone fractures, aiming to define prognostic criteria for patients' care. © 2012, Otology & Neurotology, Inc.

Roy S.,ALTAIR Engineering Inc. | Morancay L.,Altair Development France | Beauchesne E.,Altair Development France | Palaniswamy H.,ALTAIR Engineering Inc.
AIP Conference Proceedings | Year: 2011

HyperForm® and RADIOSS® which are components of the Altair® HyperWorks® software suite have been used for stamping simulation for the last fifteen years. Many features specialized for explicit stamping simulation to accurately capture the material behavior and contact phenomena have been developed over the years. Over the recent years several new innovative enhancements have been made to HyperForm and RADIOSS based on industry needs such as, analysis with fine mesh from the start of analysis for accurate spring back prediction without sacrifice of performance obtained with mesh adaptivity; high degree of scalability, reliability, quality and performance of the RADIOSS solver across multiple processors; modeling of thick sheet metal with solid elements; thermal forming for advanced high strength steels; tool stress analysis, and optimization of stamping processes and tool structures. This paper illustrates the benefits of the most recently implemented novel features in HyperForm and RADIOSS using real life examples. © 2011 American Institute of Physics.

Palaniswamy H.,ALTAIR Engineering Inc. | Kanthadai N.,Altair Engineering India Pvt. Ltd | Roy S.,ALTAIR Engineering Inc. | Beauchesne E.,Altair Development France
AIP Conference Proceedings | Year: 2011

Crash, NVH (Noise, Vibration, Harshness), and durability analysis are commonly deployed in structural CAE analysis for mechanical design of components especially in the automotive industry. Components manufactured by stamping constitute a major portion of the automotive structure. In CAE analysis they are modeled at a nominal state with uniform thickness and no residual stresses and strains. However, in reality the stamped components have non-uniformly distributed thickness and residual stresses and strains resulting from stamping. It is essential to consider the stamping information in CAE analysis to accurately model the behavior of the sheet metal structures under different loading conditions. Especially with the current emphasis on weight reduction by replacing conventional steels with aluminum and advanced high strength steels it is imperative to avoid over design. Considering this growing need in industry, a highly automated and robust method has been integrated within Altair Hyperworks® to initialize sheet metal components in CAE models with stamping data. This paper demonstrates this new feature and the influence of stamping data for a full car frontal crash analysis. © 2011 American Institute of Physics.

Toma M.,Altair Development France | Njilie F.E.A.,Altair Development France | Ghajari M.,Imperial College London | Galvanetto U.,Imperial College London
International Journal of Simulation Modelling | Year: 2010

Motorcycle crash-related fatalities and injuries have a relatively increasing tendency compared to other vehicles. The new development of safety devices and technologies for prediction of their behaviour are therefore also increasingly important. Motorcycles have the least amount of protective devices amongst vehicles. A small disturbance in the motion of motorcycles can expose the riders to severe impacts leading to injuries especially in the appendicular part of the body, but the severest injury is usually to the head. Head injuries are the most common cause of death amongst motorcyclists (approximately 45 %). Thus, naturally, the main protective equipment preventing motorcyclists from fatal injuries is the helmet. In this study, detailed finite element models of helmet and human head are used to simulate and analyse the impacts on a protected and unprotected head in a scenario typical for motorcycle-related collisions.

Thollon L.,Aix - Marseille University | Godio Y.,Aix - Marseille University | Bidal S.,Altair Development France | Brunet C.,Aix - Marseille University
International Journal of Crashworthiness | Year: 2010

A study sponsored by National Highway Traffic Safety Administration (NHTSA) in 1981 showed that the most deadly injuries to the accident victims were injuries of the chest and head. In this context, the present paper focuses on the use of the numerical simulation to predict rib fractures in case of motorcycle accidents and to evaluate a new safety system, i.e. an airbag integrated in the jacket. Different simulations were performed, with and without airbag, according to experimental tests (pendulum subsystem tests with post-mortem human subjects (PMHS)) to evaluate the influence of various parameters. For each configuration test, we analysed the load versus time curve of the pendulum and performed an injury report to evaluate ribs fractures. Concerning the airbag system, the study showed that this type of protection increases motocyclist's security. Indeed, for each simulations test, performed with airbag, no injuries were noted when the airbag was used. © 2010 Taylor & Francis.

Ruiz D.G.,CIDAUT | Magallon B.P.,CIDAUT | Peldschus S.,Ludwig Maximilians University of Munich | Schuller E.,Ludwig Maximilians University of Munich | And 2 more authors.
International Journal of Crashworthiness | Year: 2010

The problem of injuries to motorcyclists caused by impacts with roadside barriers is not a recent issue (S. Peldschus, E. Schuller, J. Koenig, M. Gaertner, D. Garcia, and A. Mansilla, Technical bases for the development of a test standard for impacts of powered two-wheelers on roadside barriers, Proceedings of the 20th Enhanced Safety of Vehicles Conference, 2007) but at present, few standards have been proposed in this field. In APROSYS SP4 'Motorcycle accidents', one of the main objectives is to develop a proposal of test procedure to evaluate road infrastructure in terms of motorcyclists' safety. For that purpose, it is necessary to know which are the most representative scenarios describing real motorcyclists' impacts against the infrastructure. Conclusive results have been obtained neither from the database analysis nor from the literature review. A theoretical study, reconstruction of accidents and a computer simulation work have been performed in order to select the parameters to be used in the standard proposal. On the other hand, no crash-test dummies are available (specifically developed and validated) for this application. The use of similar test standards and a numerical human body model aiming to modify an existing (Hybrid III) dummy are seen to be the most applicable steps to improve the described situation in the medium term. Accordingly, injury criteria have been defined for head, neck and thorax. This paper describes the work methodology that has been followed for the establishment of guidelines which can lead to a future European Standard for the assessment of roadside furniture performance.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: SST-2007-4.1-01;SST-2007-4.1-07 | Award Amount: 4.77M | Year: 2009

Computer aided engineering is a routinely used technology for the design and testing of road vehicles, including the simulation of their response to an impact and the prediction of the risk of injuries sustained by the potential victims. But, so far, the release of a vehicle on the market still depends on the verification of the product compliance with safety standards through a series of type approval physical tests. To increase car industry competitiveness by reducing the burden of this type approval test system and to improve road safety by raising the quality level of protection measures, recent initiatives have been taken by both industry and public authorities, to promote the use of alternative ways (e.g. virtual test through numerical simulation) to check vehicle compliance with safety standards. The main objective of this project is the implementation of virtual (VT) procedures in existing safety standards by consolidation of advanced VT technologies, analyzing the ensuing costs and benefits and looking for the improvement of homologation procedures as well as setting the base for improvement of integrative safety. The achievement of this objective implies among others, that the accuracy of the simulation models and procedures can be assured and rated independently of the modelling process, software tools, computing platform and the performing organization (end user). Procedures that consider uncertainties due to different real tests results (depending on the lab performing), input parameters dispersion, etc. will be taken into account in these processes. In this project, the future potential of Virtual Testing will be investigated not only to fully substitute real testing (RT) in regulations but also to define procedures for fully virtual testing including biomechanics validation of real and virtual test devices and to evaluate transferring the process of VT to new advanced safety systems (active and pre-crash safety systems).

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