Significant Severity Reduction of Side-Impact Injuries by Using ITS Airbags: FE Simulation and Severity Analysis

Author(s):  
Tarek A. Omar ◽  
Nabih E. Bedewi ◽  
Azim Eskandarian

The Inflatable Tubular Structure (ITS) airbag is a potentially life-saving device that has been implemented recently in some luxury vehicles. Its main objective is to provide head protection for the front seat occupants against upper side-interior car components. In a previous research conducted by the authors, a nonlinear Finite Element (FE) model for the ITS-airbag system was successfully developed and tested. In the current research, the developed ITS model is combined with a full-scale FE vehicle model and 50th percentile side-impact dummy (SID) model. The combined model is then used to conduct two series of side-impact simulations. The first series included side impacts with narrow objects, i.e. rigid poles, while the second series included side impacts with a Moving Deformable Barrier (MDB) as a wide and deformable object. The effect of the relative position between the dummy and the rigid pole was considered by conducting variety of simulations for two different rigid pole positions and three different dummy positions. The three dummy positions were considered in the side impacts with the MDB. For both impact series, the effect of the impact velocity was considered by conducting each impact scenario at three different velocities. The ITS model performance, in all FE simulations, was fairly similar to the actual ITS performance. The simulation results indicated a significant reduction in the Head Injury Criteria (HIC) of the dummy head due to the ITS-airbag deployment. The life-threatening severity for occupants is usually measured by the Abbreviated Injury Scale (AIS) that ranges from 1 (minor) to 6 (fatal). The AIS indices are calculated in all side impacts. The results demonstrated a significant reduction/elimination in fatalities and severe injuries due to the ITS-airbag performance. The results clearly indicated the great benefits expected from this promising safety device.

2013 ◽  
Vol 456 ◽  
pp. 38-42
Author(s):  
Ai Hong Gong ◽  
Ming Mao Hu

Based on the finite element (FE) model and Moving Deformable barrier (MDB) model of a car side impact, the virtual test of the side impact was conducted with HYPERWORK software according to Euro-NCAP regulation. Then the impact performance was evaluated in both deformation and response curve of the car body, and the problem of the crashworthiness in designing the side structure was analyzed. Finally, the structure improvement with CATIA for the side crashworthiness was proposed. Keywords: CAE analyze, Side impact, Improvement


2001 ◽  
Author(s):  
Tarek A. Omar ◽  
Wolfgang Rehm ◽  
Nabih E. Bedewi ◽  
Ali Al-Fraiji

Abstract The Inflatable Tubular Structure (ITS) airbag is a potentially life-saving device that has been implemented recently in some luxury passenger vehicles. When deployed, the ITS-airbag provides primarily protection of the front seat occupant’s head and face against upper side-interior car components. In the current research, a nonlinear Finite Element (FE) model for ITS-airbag system was proposed, developed, and tested in a side impact using dummy-head and neck FE model. The modeling technique of the unique behavior of the outer layer of the ITS-airbag is explained in details. Modeling such a complicated behavior of the ITS (axial shrinkage and radial expansion) was successfully performed by using a combination of diagonal truss elements combined with an isotropic fabric material. Nonlinear FE side-impact simulations for a Hybrid-III dummy-head and neck model impacting a vehicle’s side glassing, roof-rail, and B-pillar using the ITS airbag system were conducted using the explicit FE code LS-DYNA. The developed ITS model has reduced the Head Injury Criteria (HIC) and the peak-acceleration of the dummy-head significantly. The results indicated the ability of the developed finite element model to represent the real ITS airbag system and therefore provide a reliable nonlinear FE simulation results that could be used to test, improve, and validate the implementation of the ITS airbag systems in more vehicles.


Author(s):  
Zuoping Li ◽  
Jong-Eun Kim ◽  
Jorge E. Alonso ◽  
James S. Davidson ◽  
Alan W. Eberhardt

Clearer understanding of the biomechanics of the pubic symphysis in lateral pelvic impact tests may serve to elucidate the mechanisms of injury in automotive side impacts. While numerous experimental and computational studies have been conducted on the human pelvis, stresses and deformations of the symphysis were never measured, and the role of the boundary conditions supporting the pelvis was not emphasized. The objective of the present study was to develop a biofidelic FE model to investigate the deformations and stresses experienced by the pubic ligaments and interpubic disc under side impact conditions simulating both drop tower experiments and automotive side impacts.


2019 ◽  
Vol 18 (3) ◽  
pp. 557-566
Author(s):  
Mohammed Rajik Khan ◽  
Atul Sonawane

Purpose This paper aims to present 3D finite element (FE) simulations of impact loading on a construction safety helmet over a headform to improve the ventilation slots profile in helmet design. Design/methodology/approach Impact response on headforms in three different studies considering ventilation slots of varied profiles and dimensions in helmets with rectangular elliptical and circular slots is compared and analysed. Head injury criteria (HIC) and safety regulations from past literature have been considered to evaluate the impact responses. Findings Simulation results show that a helmet with rectangular ventilation slots achieves a lowest peak impact force of 5941.3 N for a slot area of 170 mm2 as compared to elliptical and circular slots. Research limitations/implications Ventilation slots of simple geometry (rectangular, elliptical and circular) have been considered in this work. Other/complex geometry slots can also be chosen to predict its effect during impact response on a helmet–headform model. Biofidelic head–neck FE model can be developed to achieve precise results. Practical implications The presented work gives a clear idea to design engineers for the selection of ventilation slot profiles to design a construction safety helmet. Social implications Construction safety (CS) helmets are used to reduce injuries on heads of workers at construction sites in the event of free-falling objects. Rectangular ventilation slots in CS helmets as suggested in the work may reduce the risk of injury. Originality/value Results are found in good agreement with the past numerical simulation of impact response on a construction safety helmet over a validated biofidelic head FE model.


2012 ◽  
Vol 9 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Blaine Hoshizaki ◽  
Michael Vassilyadi ◽  
Andrew Post ◽  
Anna Oeur

Object The purpose of this study was to evaluate how currently used helmets would perform for winter play activities, such as tobogganing. In Canada and northern parts of the US, the advent of winter is followed by an increase in visits to hospital emergency departments by young children presenting with head injuries resulting from winter activities. Sliding, skating, skiing, and snowboarding all involve risks of head injury from situations such as falling on ice or sliding into stationary objects. This study compared the protective characteristics of helmets used by young children (< 7 years of age) participating in winter recreational activities. Methods Ice hockey, alpine ski, and bicycling helmets were impacted at 2.0, 4.0, 6.0, and 8.0 m/second at the front and side impact location by using a monorail drop rig. Results The results for the front impact showed that the ice hockey helmet protected the child significantly better at 2 and 4 m/second when considering both linear and angular peak acceleration. The bicycle helmet performed significantly better than the other 2 helmets at 8 m/second for the front location and only angularly for the side impacts. Conclusions Depending on the impact velocity of the hazard, the type of helmet significantly affected the risk of brain injury.


Aerospace ◽  
2019 ◽  
Vol 6 (9) ◽  
pp. 95
Author(s):  
Giuseppe Lamanna ◽  
Amalia Vanacore ◽  
Michele Guida ◽  
Francesco Caputo ◽  
Francesco Marulo ◽  
...  

This paper deals with the redesign of an aircraft passenger seat, placed at the first seat row, which was not compliant with Federal Aviation Regulations FAR 25.562 “Emergency landing dynamic conditions” regulation (due to a high value for the Head Injury Criterion (HIC)) and related guidelines. Starting from an accurate analysis of some results obtained via an experimental seat sled test, a numerical procedure was developed in order to improve the passenger safety with respect to head injury. Specifically, the proposed numerical procedure, using the advantages of a Finite Element (FE) model and a Design of Experiment (DoE) approach for simulation modeling, was aimed at identifying a new design solution to avoid the impact between the passenger’s head and the bulkhead. The redesign of the passenger seat was validated against an experimental test carried out at Geven S.p.A. Company by demonstrating, consequently, the compliance of the modified seat-belt system with the regulations.


Author(s):  
S.P. Sundar Singh Sivam ◽  
Ganesh Babu Loganathan ◽  
K. Saravanan ◽  
V.G. Umasekar ◽  
T.P. Mohammed Rameez

Automotive side impacts are particularly dangerous as location of impact is very close to the passenger, who can be immediately reached by the impacting vehicle. FMVSS 214 static is a US safety regulation for occupant safety during side impacts, in which the vehicle is tested at static loading conditions to measure its load baring capacity and integrity of side closures. The CAE load case, virtually simulating the test, was handled as a quasi-static problem in this study. Impact beam is a component that helps in improving vehicle passive safety performance during side impacts by minimizing door intrusion to the occupant cabin. It plays an important role in achieving side impact regulatory norms. Through this study, a mass optimized front door impact beam design was developed for a passenger car with the help of CAE simulations; FMVSS 214S regulation norms are met. Component thickness, material and cross section shape were the design variables considered for the study. A methodology to perform the component level simulation of the impact beam loading such that it replicates component behaviour during full vehicle simulation was developed. This has helped in reducing the total problem calculation time in solver. This also has minimized the computational cost for the project. CAE simulations required for the study were done using LS-DYNA. ANSA and PRIMER were used as pre-processors and hyper-graph and meta-post were used for post processing.


Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 322
Author(s):  
Evelina Volpe ◽  
Luca Ciabatta ◽  
Diana Salciarini ◽  
Stefania Camici ◽  
Elisabetta Cattoni ◽  
...  

The development of forecasting models for the evaluation of potential slope instability after rainfall events represents an important issue for the scientific community. This topic has received considerable impetus due to the climate change effect on territories, as several studies demonstrate that an increase in global warming can significantly influence the landslide activity and stability conditions of natural and artificial slopes. A consolidated approach in evaluating rainfall-induced landslide hazard is based on the integration of rainfall forecasts and physically based (PB) predictive models through deterministic laws. However, considering the complex nature of the processes and the high variability of the random quantities involved, probabilistic approaches are recommended in order to obtain reliable predictions. A crucial aspect of the stochastic approach is represented by the definition of appropriate probability density functions (pdfs) to model the uncertainty of the input variables as this may have an important effect on the evaluation of the probability of failure (PoF). The role of the pdf definition on reliability analysis is discussed through a comparison of PoF maps generated using Monte Carlo (MC) simulations performed over a study area located in the Umbria region of central Italy. The study revealed that the use of uniform pdfs for the random input variables, often considered when a detailed geotechnical characterization for the soil is not available, could be inappropriate.


2021 ◽  
Vol 444 ◽  
pp. 109453
Author(s):  
Camille Van Eupen ◽  
Dirk Maes ◽  
Marc Herremans ◽  
Kristijn R.R. Swinnen ◽  
Ben Somers ◽  
...  

Author(s):  
Jan Mraček ◽  
Jan Mork ◽  
Jiri Dostal ◽  
Radek Tupy ◽  
Jolana Mrackova ◽  
...  

Abstract Background Decompressive craniectomy (DC) has become the definitive surgical procedure to manage a medically intractable rise in intracranial pressure. DC is a life-saving procedure resulting in lower mortality but also higher rates of severe disability. Although technically straightforward, DC is accompanied by many complications. It has been reported that complications are associated with worse outcome. We reviewed a series of patients who underwent DC at our department to establish the incidence and types of complications. Methods We retrospectively evaluated the incidence of complications after DC performed in 135 patients during the time period from January 2013 to December 2018. Postoperative complications were evaluated using clinical status and CT during 6 months of follow-up. In addition, the impact of potential risk factors on the incidence of complications and the impact of complications on outcome were assessed. Results DC was performed in 135 patients, 93 of these for trauma, 22 for subarachnoid hemorrhage, 13 for malignant middle cerebral artery infarction, and 7 for intracerebral hemorrhage. Primary DC was performed in 120 patients and secondary DC in 15 patients. At least 1 complication occurred in each of 100 patients (74%), of which 22 patients (22%) were treated surgically. The following complications were found: edema or hematoma of the temporal muscle (34 times), extracerebral hematoma (33 times), extra-axial fluid collection (31 times), hemorrhagic progression of contusions (19 times), hydrocephalus (12 times), intraoperative malignant brain edema (10 times), temporal muscle atrophy (7 times), significant intraoperative blood loss (6 times), epileptic seizures (5 times), and skin necrosis (4 times). Trauma (p = 0.0006), coagulopathy (p = 0.0099), and primary DC (p = 0.0252) were identified as risk factors for complications. There was no significant impact of complications on outcome. Conclusions The incidence of complications following DC is high. However, we did not confirm a significant impact of complications on outcome. We emphasize that some phenomena are so frequent that they can be considered a consequence of primary injury or natural sequelae of the DC rather than its direct complication.


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