scholarly journals Finite Element Analysis of the Motorcycle Helmet Material against Impact Velocity

2021 ◽  
Vol 9 (9) ◽  
pp. 979-995
Author(s):  
Arnav Gupta
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Impact Velocity ◽  
Head Injuries ◽  
Dynamic Responses ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Injury Criteria ◽  
Motorcycle Helmet ◽  
Head Injury Criteria

Abstract: A motorcycle helmet is the best protective headgear for the prevention of head injuries due to direct cranial impact. A finite element model based on realistic geometric features of a motorcycle helmet is established, and explicit finite element code is employed to simulate dynamic responses at different impact velocities. Peak acceleration and Head injury criterion values derived from the head form are used to assess the protective performance of the helmet. We have concluded that the dynamic responses of the helmet dramatically vary with impact velocity, as well as the mechanical properties of the outer shell and energy- absorbing liner. At low velocities e.g. 8.3 m/s, the shell stiffness and liner density should be relatively low to diminish head- contact force. At high velocity e.g. 11m/s, a stiffer shell and denser liner offer superior protection against head injuries. Different tests were performed in ansys explicit dynamics solver by taking different materials and calculating PLA, Head Injury Criteria, K.E, P.E, contact energy etc. The results obtained for different materials were then compared with easy other to draw the necessary conclusion’s. Keywords: Peak Linear Acceleration (PLA), Head Injury Criteria.

Head Injury in Facial Impact—A Finite Element Analysis of Helmet Chin Bar Performance

2000 ◽  
Vol 122 (6) ◽  
pp. 640-646 ◽  
Author(s):  
Chih-Han Chang ◽  
Li-Tung Chang ◽  
Guan-Liang Chang ◽  
Shyh-Chour Huang ◽  
Chiou-Hua Wang
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Head Injuries ◽  
Element Analysis ◽  
Maximum Acceleration ◽  
Explicit Finite Element ◽  
Motorcycle Helmet ◽  
Energy Absorbing ◽  
Protective Performance ◽  
The Impact

The chin bar of a motorcycle helmet protects the rider from facial and head injuries. To evaluate the protective performance of chin bars against head injuries from facial impacts, an explicit finite element method was used to simulate the Snell Memorial Foundation test and a proposed drop test. The maximum acceleration and Head Injury Criterion (HIC) were employed to assess the impact-absorbing capability of the chin bar. The results showed that the proposed approach should be more practical than the Snell test, and provided more information for improving the chin bar design to protect against head injuries. The shell stiffness was important in determining the protective ability of the chin bar, but a chin bar with only an outer shell and comfort foam offered inadequate protection. An energy-absorbing liner was essential to increase the protective performance of the chin bar and the liner density should be denser than that used in the cranial portion of the helmet. For the chin bar with energy-absorbing liner, a shell design that is less stiff would provide better protection. [S0148-0731(00)01206-1]

scholarly journals Numerical Simulation of Airbag and Study on the Effect of Airbag Parameters on Head Injury Criteria

2021 ◽  
Vol 9 (9) ◽  
pp. 1654-1666
Author(s):  
Aakash R
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Traffic Safety ◽  
Critical Role ◽  
Highway Traffic ◽  
Element Analysis ◽  
National Highway Traffic Safety ◽  
Occupant Safety ◽  
Injury Criteria ◽  
Head Injury Criteria

Abstract: In the case of an accident, inflatable restraints system plays a critical role in ensuring the safety of vehicle occupants. Frontal airbags have saved 44,869 lives, according to research conducted by the National Highway Traffic Safety Administration (NHTSA).Finite element analysis is extremely important in the research and development of airbags in order to ensure optimum protection for occupant. In this work, we simulate a head impact test with a deploying airbag and investigate the airbag's parameters. The airbag's performance is directly influenced by the parameters of the cushion such as vent area and fabric elasticity. The FEM model is analysed to investigate the influence of airbag parameter, and the findings are utilised to determine an optimal value that may be employed in the construction of better occupant safety systems. Keywords: airbag, finite element method, occupant safety, frontal airbag, vent size, fabric elasticity, head injury criteria

Finite element analysis of the effect of motorcycle helmet materials against impact velocity

2003 ◽  
Vol 26 (6) ◽  
pp. 835-843 ◽  
Author(s):  
Li‐Tung Chang ◽  
Guan‐Liang Chang ◽  
Ji‐Zhen Huang ◽  
Shyh‐Chour Huang ◽  
De‐Shin Liu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Velocity ◽  
Element Analysis ◽  
Motorcycle Helmet

scholarly journals Evaluation of Head Injury Criteria for Injury Prediction Effectiveness: Computational Reconstruction of Real-World Vulnerable Road User Impact Accidents

2021 ◽  
Vol 9 ◽  
Author(s):  
Fang Wang ◽  
Zhen Wang ◽  
Lin Hu ◽  
Hongzhen Xu ◽  
Chao Yu ◽  
...  
Keyword(s):  
Head Injury ◽  
Real World ◽  
Head Injuries ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Road User ◽  
Injury Criteria ◽  
Brain Deformation ◽  
Vulnerable Road User ◽  
Head Injury Criteria

This study evaluates the effectiveness of various widely used head injury criteria (HICs) in predicting vulnerable road user (VRU) head injuries due to road traffic accidents. Thirty-one real-world car-to-VRU impact accident cases with detailed head injury records were collected and replicated through the computational biomechanics method; head injuries observed in the analyzed accidents were reconstructed by using a finite element (FE)-multibody (MB) coupled pedestrian model [including the Total Human Model for Safety (THUMS) head–neck FE model and the remaining body segments of TNO MB pedestrian model], which was developed and validated in our previous study. Various typical HICs were used to predict head injuries in all accident cases. Pearson’s correlation coefficient analysis method was adopted to investigate the correlation between head kinematics-based injury criteria and the actual head injury of VRU; the effectiveness of brain deformation-based injury criteria in predicting typical brain injuries [such as diffuse axonal injury diffuse axonal injury (DAI) and contusion] was assessed by using head injury risk curves reported in the literature. Results showed that for head kinematics-based injury criteria, the most widely used HICs and head impact power (HIP) can accurately and effectively predict head injury, whereas for brain deformation-based injury criteria, the maximum principal strain (MPS) behaves better than cumulative strain damage measure (CSDM0.15 and CSDM0.25) in predicting the possibility of DAI. In comparison with the dilatation damage measure (DDM), MPS seems to better predict the risk of brain contusion.

Agricultural aircraft wing slat tolerance for bird strike

2017 ◽  
Vol 89 (4) ◽  
pp. 590-598 ◽  
Author(s):  
Adam Deskiewicz ◽  
Rafał Perz
Keyword(s):  
Finite Element ◽  
Impact Velocity ◽  
Structural Response ◽  
Element Model ◽  
Bird Strike ◽  
Element Analysis ◽  
Content Type ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
The Impact

Purpose The aim of this study is to assess and describe possible consequences of a bird strike on a Polish-designed PZL-106 Kruk agricultural aircraft. Due to its susceptibility to such events, a wing slat has been chosen for analysis. Design/methodology/approach Smooth particle hydrodynamics (SPH) formulation has been used for generation of the bird finite element model. The simulations were performed by the LS-Dyna explicit finite element analysis software. Several test cases have been analysed with differing parameters such as impact velocity, initial velocity vector direction, place of impact and bird mass. Findings Results of this study reveal that the structure remains safe after an impact at the velocity of 25 m/s. The influence of bird mass on slat damage is clearly observable when the impact velocity rises to 60 m/s. Another important finding was that in each case where the part did not withstand the applied load, it was the lug where first failure occurred. Some of the analysed cases indicated the possibility a consequent wing box damage. Practical implications This finding provides the manufacturer an important insight into the behaviour of the slat and suggests that more detailed analysis of the current lug design might improve the safety of the structure. Originality/value Even though similar analyses have been performed, they tended to focus on large transport aircraft components. This investigation will enhance our understanding of structural response of small, low-speed aircraft to a bird impact, which is a realistic scenario for the chosen case of an agricultural plane.

Occupant Dynamic Responses for Evaluation of Compliance Characteristics of Aircraft Bulkheads

1992 ◽  
Author(s):  
Hamid M. Lankarani ◽  
Deren Ma ◽  
Rajiv Menon
Keyword(s):  
Head Injury ◽  
Contact Force ◽  
Head Injuries ◽  
Element Model ◽  
Dynamic Responses ◽  
Instrument Panel ◽  
Force Model ◽  
Sled Test ◽  
Contact Force Model ◽  
Head Injury Criteria

Abstract One important aspect of aircraft crashworthiness studies is to reduce head injuries to an aircraft occupant in case of a head contact with its surroundings. In view of the significance of this problem, studies of post-crash dynamic behavior of victims and the compliance characteristics of the aircraft bulkhead are necessary in order to reduce severe head injuries. Crash dynamics program SOM-LA/TA, incorporating a dynamic model of the human body with a finite element model of the seat structure was used. Modifications including development of more accurate contact force models and an occupant/seat envelope were performed in SOM-LA/TA. It was then used as an analytical tool for determination of the occupant response and the compliance characteristics of the bulkhead in various crash environments. Correlated studies of analytical simulations with impact sled test results were accomplished. It was observed that the code reasonably predicted the Head-Injury-Criteria (HIC) for the triangular-shaped pulses. A parametric study of the coefficients in the contact force model was then performed in order to obtain a correlation between the HIC and the coefficients in the contact force model. A measure of optimal values for the bulkhead compliances and displacement requirements was thus achieved in order to keep the possibility of head injury as little as possible. This information could in turn be used in the selection of suitable materials for the bulkhead, instrument panel, or interior walls of an aircraft.

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