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Ballistic impact is one of the major causes for traumatic brain injury (TBI) and ballistic helmets are designed to provide protection from TBI. In real life, it is impossible to use real human subjects for experiments. Therefore, simulation based-methods are convenient to assess the rear effect to ballistic helmet impact and can provide crucial ins...
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... the later is high velocity and low masses. A ballistic helmet is able to stop handgun bullets and rifle bullets in some cases. However, the shell of the helmet is still deformed and this deformation can cause a contact between the inside of the helmet and the head. This contact may cause head tissue injury and is known as "Rear Effect" [7], [16. Fig. 1 shows the deformations on the exterior and interior surface of a steel ...
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... hits the helmet with a larger angle, the bullet has smaller deformation and less kinetic energy is transferred to the head. The results shown in Table 4 illustrate that impact angles have a great effect on the head response and deflection of the helmet. A larger angle significantly reduces the maximum v-m stress on skull bone, which is shown in Fig. 10, as well as the absolute values of the maximum/minimum pressure and maximum principal strain in the brain tissue. HIC scores given in Fig. 11 are not high enough to cause a head injury according to Fig. 2 and decrease with the increasing of the impact ...
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... in Table 4 illustrate that impact angles have a great effect on the head response and deflection of the helmet. A larger angle significantly reduces the maximum v-m stress on skull bone, which is shown in Fig. 10, as well as the absolute values of the maximum/minimum pressure and maximum principal strain in the brain tissue. HIC scores given in Fig. 11 are not high enough to cause a head injury according to Fig. 2 and decrease with the increasing of the impact ...
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... impact positions of the helmet with the 0 degree impact angle shown in Fig. 12 (front, side, top and back) are simulated. Table 5. Fig. 14 shows that the impact from the back part of the helmet generated the highest HIC score 54.52, though it is not high enough to cause a head injury. Fig. 15 shows the Von Mises stress on the skull at different time steps when the helmet is impacted at the back part by a bullet. ...
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... impact positions of the helmet with the 0 degree impact angle shown in Fig. 12 (front, side, top and back) are simulated. Table 5. Fig. 14 shows that the impact from the back part of the helmet generated the highest HIC score 54.52, though it is not high enough to cause a head injury. Fig. 15 shows the Von Mises stress on the skull at different time steps when the helmet is impacted at the back part by a bullet. The bullet that comes from the top has a HIC score of 38.24, ...
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... impact positions of the helmet with the 0 degree impact angle shown in Fig. 12 (front, side, top and back) are simulated. Table 5. Fig. 14 shows that the impact from the back part of the helmet generated the highest HIC score 54.52, though it is not high enough to cause a head injury. Fig. 15 shows the Von Mises stress on the skull at different time steps when the helmet is impacted at the back part by a bullet. The bullet that comes from the top has a HIC score of 38.24, which is more dangerous than that from the front which has a HIC score of 24.4. When the helmeted head is hit by a bullet from the side part, the HIC is ...
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... hits the other parts which are: 38.24 for the top; 24.40 for the front; 10.16 for the side. However, the HIC scores are not necessary to have the same trend as the values of Von Mises stress, maximum/minimum brain pressure or maximum principal strain in the brain because the HIC only depends on the resultant translational acceleration. As in Fig. 16, different positions of human head have non-uniform thickness distribution and the thickest part is the forehead. Therefore, Von Mises stress, maximum/minimum brain pressure, and maximum principal strain in the brain are all the smallest when the helmet is impacted at the front part compared with the other three ...
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Citations
... Equestrian helmets are designed and tested based on linear impacts [22][23][24]. Studies [21,[25][26][27][28] which have examined different helmets assess linear impact on flat anvil with different velocities (depending on the helmet use and its associated standard). Connor et al. analysed 216 real-world equestrian damaged helmets with reported head injuries so they could compare the damaged one to helmet designed with different standards [23]. ...
Polo is a popular sport in New Zealand, Australia, the United Kingdom, and many other European countries. Polo is a vigorous sport involving players and horses moving at speed and can result in head injuries caused by falls. Helmets play a vital role in the safety and protection of polo players. This study investigates different hemispheric bumper shapes of the helmet to improve the impact resistance performance using finite element analysis (FEA) and Explicit Dynamic Analysis (EDA). The aerodynamic performance of the proposed helmet is investigated using computational fluid dynamics (CFD) to account for drag impact on the polo player's speed. These are investigated for impact resistance and the drag coefficient under different speeds. The EDA results show that the new proposed bumper will absorb the impact and reduce the energy transferred to the inside foam at a relative impact speed of 6.2 m/s, as recommended by the U.S. Consumer Product Safety Commission (CPSC), with a maximum total deformation of 4.42 mm compared to 4.19 mm and 3.85 mm for impact speeds of 5.9 m/s by the European standard PAS 015:2011 helmets for equestrian use and 5.42 m/s BS EN 1078 helmets for bicyclists' use, respectively. Additionally, under speeds ranging from 15 km/h to 65 km/h, the new helmet demonstrated a drag coefficient of 0.454, similar to that of the national team helmet, at 0.423.
... However, there has been limited research on the biomechanical response to ballistic impact based on accelerations and pressures affecting the brain and deformations produced in the skull both experimentally [13,14] and numerically [15][16][17][18][19]. Some authors have performed ballistic impact tests on combat helmets using head simulants instrumented with accelerometers and pressure sensors [20][21][22]. ...
... The first one is usually used to assess the protective capacity of the helmet in some games, e.g. football [7][8][9], ice hockey [10], heavy industry [11,12] and combat [13,14]. However, in the impact test of a bicycle or motorcycle helmet, the helmet often has an initial velocity and impacts onto an obstacle, such as anvil, road and vehicle. ...
In a bicycle–vehicle or a motorcycle–vehicle accident, the head of an adult rider with a helmet is very likely to impact the windshield laminated glass. Such a complex impact phenomenon normally involves head injury, windshield failure, and helmet damage. The main purpose of this work is to present a computational framework for modeling the impact interaction between a helmeted headform and a windshield glazing. To achieve this, a finite element helmet model is established, where a crushable foam model and a continuum damage mechanics based fracture model are used to describe helmet composite failure. The accuracy of the model is validated by comparing the numerical results with the corresponding experimental data. For the windshield failure, we adopt the commonly used intrinsic cohesive zone model to account for two main failure patterns, i.e., glass fracture and glass–PVB debonding. The mechanical responses of a helmeted headform are compared with those of a pure headform to investigate the protective performance of the helmet. Finally, parametric studies are carried out to numerically investigate the effects of impact velocity, helmet posture, and impact location on the windshield on headform response.
... In the present work, this task was done through the inclusion of a set of discrete elements with finite spring stiffness. The stiffness of these elements was determined and validated by comparison with tests done by Yang and Dai [29]. Tests were done with stiffness values ranging from 0.0001 to 1; 000kN/mm for the 0 + and 45 + impact angles, and from the comparison with the results of Yang and Dai [29] the stiffness was determined to be K ¼ 0:001kN/mm. ...
... The stiffness of these elements was determined and validated by comparison with tests done by Yang and Dai [29]. Tests were done with stiffness values ranging from 0.0001 to 1; 000kN/mm for the 0 + and 45 + impact angles, and from the comparison with the results of Yang and Dai [29] the stiffness was determined to be K ¼ 0:001kN/mm. ...
... The development of efficient protection systems and better and more adequate evaluation and analysis methods [29] is essential in the process to reduce serious lesions and/or fatal injuries arising from direct or indirect impacts on the head. ...
The need to develop armour systems to protect against attacks from various sources is increasingly a matter of personal, social and national security. To develop innovative armour systems it is necessary to monitor developments being made on the type, technology and performance of the threats (weapons, projectiles, explosives, etc.) Specifically, the use of high protection level helmets on the battlefield is essential. The development of evaluation methods that can predict injuries and trauma is therefore of major importance. However, the risk of injuries or trauma that can arise from induced accelerations is an additional consideration. To develop new materials and layouts for helmets it is necessary to study the effects caused by ballistic impacts in the human head on various scenarios. The use of numerical simulation is a fundamental tool in this process. The work here presented focuses on the use of numerical simulation (finite elements analysis) to predict the consequences of bullet impacts on military helmets on human injuries. The main objectives are to assess the level and probability of head trauma using the Head Injury Criterion, caused by the impact of a 9 mm NATO projectile on a PASGT helmet and to quantify the relevance of projectile plasticity on the whole modelling process. The accelerations derived from the impact phenomenon and the deformations caused on the helmet are evaluated using fully three-dimensional models of the helmet, head, neck and projectile. Impact studies are done at impact angles ranging from 0 to 75º. Results are presented and discussed in terms of HIC and probability of acceleration induced trauma levels. Thorough comparison analyses are done using a rigid and a deformable projectile and it is observed that plastic deformation of the projectile is a significant energy dissipation mechanism in the whole impact process.
... During the operation of complex technical systems such as internal combustion engines Chybowski and Kazienko, 2019;Chybowski and Matuszak, 2007), wheeled vehicles (Fábio et al., 2018;Ptak et al. 2019), industrial robots (Gao and Wampler, 2009) or work machines (Karliński et al., 2019;Karliński et al., 2014;Karliński et al., 2016) there are situations in which the heads of operators and bystanders can be injured (Kaczyński et al., 2019;Ratajczak et al., 2019;Wilhelm et al., 2017). The risk of injury can be significantly reduced by using suitable protective covers made of modern materials (Gawdzińska, 2017;Gawdzińska et al., 2018;Gawdzińska, et al., 2016;Gawdzińska et al., 2019;, the use of personal protective equipment Fernandes et al., 2014;Kaczyński et al., 2019;Yang and Dai, 2010) and strict adherence to operational procedures Gawdzińska, 2016a, 2016b;Chybowski et al., 2006;Chybowski et al., 2016;Piasecki et al., 2017). To measure the likelihood of a head injury due to an impact, the Head Injury Criterion (HIC) is often used (McHenry, 2004): ...
... (Gennarelli and Wodzin, 2006) There are other classifications. For example according to Canadian Playground Advisory, a minor head injury occurs when there is a skull trauma without loss of consciousness, superficial face injuries, and fracture of nose or teeth (Yang and Dai, 2010). A moderate head injury occurs when there is a skull trauma with or without dislocated skull fracture and brief loss of consciousness, fracture of facial bones without dislocation, and deep wounds (Yang and Dai, 2010). ...
... For example according to Canadian Playground Advisory, a minor head injury occurs when there is a skull trauma without loss of consciousness, superficial face injuries, and fracture of nose or teeth (Yang and Dai, 2010). A moderate head injury occurs when there is a skull trauma with or without dislocated skull fracture and brief loss of consciousness, fracture of facial bones without dislocation, and deep wounds (Yang and Dai, 2010). A critical head injury occurs when there is a loss of consciousness for more than 12 hours with intracranial haemorrhaging, recovery is uncertain, cerebral contusion, and other neurological signs (Yang and Dai, 2010). ...
The paper presents a review of the basic literature on the determination of head injury effects. Introduction to the subject of Head Injury Criterion (HIC) applications as likelihood of head injury measures was made. Individual levels of Abbreviated Injury Scale (AIS) were listed as a representation of the consequences of head injury. Prasad and Mertz curves describing the relationship between the HIC value and the probability of injury for a given AIS level were presented. Exponential models, developed by the authors, representing individual curves were presented. The probability of head injuries at different AIS levels was estimated for selected case studies presented in the literature devoted to human workplace safety. The analysis was concluded with debate and conclusions on the use of the proposed models.
... During the operation of complex technical systems such as internal combustion engines Chybowski and Kazienko, 2019;Chybowski and Matuszak, 2007), wheeled vehicles (Fábio et al., 2018;Ptak et al. 2019), industrial robots (Gao and Wampler, 2009) or work machines (Karliński et al., 2019;Karliński et al., 2014;Karliński et al., 2016) there are situations in which the heads of operators and bystanders can be injured (Kaczyński et al., 2019;Ratajczak et al., 2019;Wilhelm et al., 2017). The risk of injury can be significantly reduced by using suitable protective covers made of modern materials (Gawdzińska, 2017;Gawdzińska et al., 2018;Gawdzińska, et al., 2016;Gawdzińska et al., 2019;, the use of personal protective equipment Fernandes et al., 2014;Kaczyński et al., 2019;Yang and Dai, 2010) and strict adherence to operational procedures Gawdzińska, 2016a, 2016b;Chybowski et al., 2006;Chybowski et al., 2016;Piasecki et al., 2017). To measure the likelihood of a head injury due to an impact, the Head Injury Criterion (HIC) is often used (McHenry, 2004): ...
... (Gennarelli and Wodzin, 2006) There are other classifications. For example according to Canadian Playground Advisory, a minor head injury occurs when there is a skull trauma without loss of consciousness, superficial face injuries, and fracture of nose or teeth (Yang and Dai, 2010). A moderate head injury occurs when there is a skull trauma with or without dislocated skull fracture and brief loss of consciousness, fracture of facial bones without dislocation, and deep wounds (Yang and Dai, 2010). ...
... For example according to Canadian Playground Advisory, a minor head injury occurs when there is a skull trauma without loss of consciousness, superficial face injuries, and fracture of nose or teeth (Yang and Dai, 2010). A moderate head injury occurs when there is a skull trauma with or without dislocated skull fracture and brief loss of consciousness, fracture of facial bones without dislocation, and deep wounds (Yang and Dai, 2010). A critical head injury occurs when there is a loss of consciousness for more than 12 hours with intracranial haemorrhaging, recovery is uncertain, cerebral contusion, and other neurological signs (Yang and Dai, 2010). ...
... In the previous ten years, Jazi et al. [4], Yang and Dai [5], Pintar et al. [6], and Tse et al. [7] established the human head biomechanical simulation model and used cadaveric experiments for validations; the finite element method was used widely from then on. ...
... What is more, there are also studies on other parameters. For example, Yang and Dai [5] established a human brain biomechanical simulation model and carried out simulation analysis of brain damage caused by the bullet impact at different angles and different positions. Tan et al. [20] researched on both experiments and numerical simulations of frontal and lateral ballistic impacts on the Hybrid III headform equipped with Advanced Combat Helmets (ACH). ...
The mechanism of Behind Helmet Blunt Trauma (BHBT) caused by a high-speed bullet is difficult to understand. At present, there is still a lack of corresponding parameters and test methods to evaluate this damage effectively. The purpose of the current study is therefore to investigate the response of the human skull and brain tissue under the loading of a bullet impacting a bullet-proof helmet, with the effects of impact direction, impact speed, and impactor structure being considered. A human brain finite element model which can accurately reconstruct the anatomical structures of the scalp, skull, brain tissue, etc., and can realistically reflect the biomechanical response of the brain under high impact speed was employed in this study. The responses of Back Face Deformation (BFD), brain displacement, skull stress, and dura mater pressure were extracted from simulations as the parameters reflecting BHBT risk, and the relationships between BHBT and bullet-proof equipment structure and performance were also investigated. The simulation results show that the frontal impact of the skull produces the largest amount of BFD, and when the impact directions are from the side, the skull stress is about twice higher than other directions. As the impact velocity increases, BFD, brain displacement, skull stress, and dura mater pressure increase. The brain damage caused by different structural bullet bodies is different under the condition of the same kinetic energy. The skull stress caused by the handgun bullet is the largest. The findings indicate that when a bullet impacts on the bullet-proof helmet, it has a higher probability of causing brain displacement and intracranial high pressure. The research results can provide a reference value for helmet optimization design and antielasticity evaluation and provide the theoretical basis for protection and rescue.
... depression or psychosis, which might lead to post-traumatic stress disorder [6,10] The importance of studies on behind helmet head trauma is unquestionable. Most research use physical models, live animals or cadaveric specimens [2,3,9,[11][12][13][14][15] or, on the other hand, numerical modelling and simulations [9,[15][16][17][18][19]. The use of knowledge gained in such research should be crucial in developing new armour designs and test standards as well. ...
... The research, which is dedicated to cyclists, focussed exemplarily on the phenomenon of oblique impacts. This form of [6] motion is representative for most impact scenarios of cyclists and motorcyclists [10]. The focus is set as well in the here presented approach to real collision conditions, such as the multi-impact effect, oblique impact and collision with a long element with a small cross-section. ...
Motorcycle crashes are an increasing road safety problem in the world, as this mean of transport has become a popular way to avoid traffic congestion, as well as a way to reduce the overall transportation cost, especially in developing countries. Currently, riding a motorcycle is also a lifestyle for many people. This publication presents a numerical approach to the subject of traffic accident involving a motorcyclist impacting a new on the market roadside barrier. Currently, there are still not explored construction solutions. The focus of the research is the determination of risk and potential consequences of motorcycle injuries using finite element method (LS-DYNA) coupled with multibody dummy model (MADYMO). Among many crash-tests carried out, there are still few simulations with the participation of motorcycles. The research conducted by authors is intended to draw attention on danger, to which some of the vulnerable road users are exposed. The paper points also on the overall complex motion and specific head-to-barrier impact – especially when neck injuries are concerned.
... Based on a combined analytical and live animal experimental investigation of brain injury, Ward et al. 37 proposed that serious and fatal injuries occur when the ICP exceeds 235 kPa, while no or minor brain injuries would occur when the ICP are below 173 kPa. In addition to the aforementioned intracranial injury metric, the von Mises stress has been commonly utilised in numerous studies in the literature 38,39 , for the measurement of skeletal stress magnitude. In the current study, von Mises stresses were chosen as the biomechanical metric for analysis of the skull, as this parameter serves as an equivalent value for gauging the intensity of impact to the skull. ...
Background
Blast-induced traumatic brain injury is the most prevalent injury sustained by combat soldiers at the frontline. The current study aims to investigate the effectiveness of composite polycarbonate-aerogel face shields with different configurations in mitigating blast-induced brain injuries.
Method
A series of dynamic fluid–structure interaction simulations of a helmeted head subjected to a frontal free field blast was performed, to evaluate the effectiveness of the current conventional polycarbonate face shield and three other composite face shields with different configurations when exposed to a frontal free-field blast.
Results
The simulation results demonstrated that the sandwiched structured face shields of polycarbonate and aerogel provided superior blast attenuation than a single-layered polycarbonate face shield. The alternate multi-layered transparent materials of high and low densities provided the best attenuation of blast pressure transmission to the head, with the polycarbonate exterior shell casing contributing to the structural integrity of the face shield, while the lower dense aerogel filler providing high acoustic impedance to blast wave transmission.
Conclusion
This study provides further insights on future development and design of personal protective equipment in mitigating blast-induced injuries to the head.
