scholarly journals A Study on Influence of Minivan Front-End Design and Impact Velocity on Pedestrian Thorax Kinematics and Injury Risk

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Fang Wang ◽  
Chao Yu ◽  
Guibing Li ◽  
Yong Han ◽  
Bingyu Wang ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Injury Risk ◽  
Research Work ◽  
Thoracic Injury ◽  
Chinese Market ◽  
Computational Biomechanics ◽  
Front End ◽  
Vehicle Impact ◽  
Pedestrian Impact ◽  
The Impact

Thoracic injuries occur frequently in minivan-to-pedestrian impact accidents and can cause substantial fatalities. The present research work investigates the human thoracic responses and injury risks in minivan-to-pedestrian impacts, when changing the minivan front-end design and the impact velocity, by using computational biomechanics model. We employed three typical types of minivan model of different front-end designs that are quite popular in Chinese market and considered four impact velocities (20, 30, 40, and 50 km/h). The contact time of car to thorax region (CTCTR), thorax impact velocity, chest deformation, and thoracic injury risks were extracted for the investigation. The results indicate that the predicted pedestrian kinematics, injury responses, and thoracic injury risks are strongly affected by the variation of the minivan front-end design and impact velocity. The pedestrian thoracic injury risks increase with the increasing vehicle impact velocity. It is also revealed that the application of the extra front bumper is beneficial for reducing the thoracic injury risk, and a relatively flatter minivan front-end design gives rise to a higher thoracic injury risk. This study is expected to be served as theoretical references for pedestrian protection design of minivans.

Effects of Vehicle Impact Velocity, Vehicle Front-End Shapes on Pedestrian Injury Risk

2012 ◽  
Vol 13 (5) ◽  
pp. 507-518 ◽  
Author(s):  
Yong Han ◽  
Jikuang Yang ◽  
Koji Mizuno ◽  
Yasuhiro Matsui
Keyword(s):  
Impact Velocity ◽  
Injury Risk ◽  
Front End ◽  
Pedestrian Injury ◽  
Vehicle Impact

Effects of vehicle front-end safety countermeasures on pedestrian head injury risk during ground impact

2019 ◽  
Vol 233 (14) ◽  
pp. 3588-3599 ◽  
Author(s):  
Liangliang Shi ◽  
Yong Han ◽  
Hongwu Huang ◽  
Wei He ◽  
Fang Wang ◽  
...  
Keyword(s):  
Injury Risk ◽  
Rotation Angle ◽  
Head Injuries ◽  
Leading Edge ◽  
Vehicle Safety ◽  
Secondary Impact ◽  
Front End ◽  
Vehicle Impact ◽  
Safety Countermeasures ◽  
Primary Impact

Pedestrian safety countermeasures such as pop-up bonnets and exterior pedestrian airbags have been shown to decrease the pedestrian injury risk caused by vehicle impacts (primary impact). However, it is still unknown whether these devices could prevent or mitigate pedestrian injuries resulting from ground impacts (secondary impact). In order to understand how the vehicle safety countermeasures prevent pedestrian head injuries caused by primary and secondary impacts, a total of 252 vehicle-to-pedestrian impact simulations were conducted using the MADYMO code. The simulations accounted for three types of vehicle configurations (a baseline vehicle and vehicles with the two aforementioned vehicle safety countermeasures) along with five front-end structural parameters at three vehicle impact velocities (30, 40, and 50 km/h). The simulation results show that the bonnet leading edge height was the most sensitive parameter affecting the head-to-vehicle impact location and that caused different head injuries resulting from the local stiffness in the location impacted. Moreover, the bonnet leading edge height was the leading governing factor on the pedestrian rotation angle in the secondary impact. The vehicle equipped with a pop-up bonnet and an external airbag could cause a larger pedestrian rotation angle at 30 km/h than that in the other two vehicle types, but conversely could cause a smaller pedestrian rotation angle at 40 and 50 km/h. Also, the vehicle equipped with pop-up bonnet and external airbag systems could lead a higher pedestrian flight altitude than that of the baseline type. A vehicle equipped with a pop-up bonnet and external airbag systems provide improved protection for the pedestrian’s head in the primary impact, but may not prevent the injury risk and/or even cause more severe injuries in secondary impacts.

scholarly journals Realistic Reference for Evaluation of Vehicle Safety Focusing on Pedestrian Head Protection Observed From Kinematic Reconstruction of Real-World Collisions

2021 ◽  
Vol 9 ◽  
Author(s):  
Guibing Li ◽  
Jinming Liu ◽  
Kui Li ◽  
Hui Zhao ◽  
Liangliang Shi ◽  
...  
Keyword(s):  
Head Injury ◽  
Impact Velocity ◽  
Real World ◽  
Contact Time ◽  
Injury Risk ◽  
Safety Performance ◽  
Contact Boundary ◽  
Vehicle Safety ◽  
Pedestrian Protection ◽  
Vehicle Impact

Head-to-vehicle contact boundary condition and criteria and corresponding thresholds of head injuries are crucial in evaluation of vehicle safety performance for pedestrian protection, which need a constantly updated understanding of pedestrian head kinematic response and injury risk in real-world collisions. Thus, the purpose of the current study is to investigate the characteristics of pedestrian head-to-vehicle contact boundary condition and pedestrian AIS3+ (Abbreviated Injury Scale) head injury risk as functions of kinematic-based criteria, including HIC (Head Injury Criterion), HIP (Head Impact Power), GAMBIT (Generalized Acceleration Model for Brain Injury Threshold), RIC (Rotational Injury Criterion), and BrIC (Brain Injury Criteria), in real-world collisions. To achieve this, 57 vehicle-to-pedestrian collision cases were employed, and a multi-body modeling approach was applied to reconstruct pedestrian kinematics in these real-world collisions. The results show that head-to-windscreen contacts are dominant in pedestrian collisions of the analysis sample and that head WAD (Wrap Around Distance) floats from 1.5 to 2.3 m, with a mean value of 1.84 m; 80% of cases have a head linear contact velocity below 45 km/h or an angular contact velocity less than 40 rad/s; pedestrian head linear contact velocity is on average 83 ± 23% of the vehicle impact velocity, while the head angular contact velocity (in rad/s) is on average 75 ± 25% of the vehicle impact velocity in km/h; 77% of cases have a head contact time in the range 50–140 ms, and negative and positive linear correlations are observed for the relationships between pedestrian head contact time and WAD/height ratio and vehicle impact velocity, respectively; 70% of cases have a head contact angle floating from 40° to 70°, with an average value of 53°; the pedestrian head contact angles on windscreens (average = 48°) are significantly lower than those on bonnets (average = 60°); the predicted thresholds of HIC, HIP, GAMBIT, RIC, BrIC2011, and BrIC2013 for a 50% probability of AIS3+ head injury risk are 1,300, 60 kW, 0.74, 1,470 × 104, 0.56, and 0.57, respectively. The findings of the current work could provide realistic reference for evaluation of vehicle safety performance focusing on pedestrian protection.

Physico-mechanical and erosive wear analysis of polyester fibre-based nonwoven fabric-reinforced polymer composites

2018 ◽  
Vol 49 (4) ◽  
pp. 447-464 ◽  
Author(s):  
Sachin Tejyan ◽  
Tej Singh ◽  
Amar Patnaik ◽  
Gusztáv Fekete ◽  
Brijesh Gangil
Keyword(s):  
Impact Velocity ◽  
Polyester Fibre ◽  
Research Work ◽  
Erosive Wear ◽  
Nonwoven Fabric ◽  
Fibre Content ◽  
Epoxy Composites ◽  
Wear Behaviour ◽  
Air Jet ◽  
The Impact

The research work aims to study the physico-mechanical and erosive wear behaviour of polyester fibre-based needle-punched nonwoven fabric mat reinforced epoxy composites. Therefore, the epoxy composites with varying proportion of polyester fibre-based needle-punched nonwoven fabric mat were fabricated and characterized for their physical, mechanical and erosive wear properties. The experimental results indicated that the increase of fibre content enhanced the physical and mechanical properties of the composites. To optimize and improve the erosive wear performance of fabricated composites, the Taguchi method was implemented. For this, L27 orthogonal array was constructed to examine the influence of the five control factors including impingement angle, impact velocity, stand-off distance, fibre content and erodent size. The experimental schedule was carried out in an air jet erosion test rig. The results indicate that the impact velocity emerges as the most significant control factor affecting the erosive wear of fabricated composites. Finally, the possible erosive wear mechanisms were studied by examining the composites eroded surfaces with scanning electron microscopy.

Numerical Simulation of Piezoelectric Sensor Used in a New Pedestrian Protection System

Volume 3 ◽  
2004 ◽  
Author(s):  
Renzo Capitani ◽  
Tommaso Iacomelli ◽  
Enrico Gobetto
Keyword(s):  
Experimental Analysis ◽  
Structural Characteristics ◽  
Sensor System ◽  
Crash Test ◽  
Electric Signal ◽  
Pedestrian Protection ◽  
Fem Model ◽  
Front End ◽  
Pedestrian Impact ◽  
The Impact

In recent years, pedestrians have been involved in many accidents. Statistics show that in Europe pedestrians are involved in 12% of the accidents and 20% of road users who lose their life in accidents are pedestrians. Authorities and automobile manufacturers are interested to reduce the physical damages of these users. The EU requires a very accurate design of new car front-end, because this is the first part involved in the car-to-pedestrian impact. Some EU organisations as EEVC (European Enhanced Vehicle-Safety Committee- Working Group 17) and ACEA (Association des Constructeurs Europeens d’Automobiles) have decided the directives on the design of the new car front-end. These documents settle on the experimental methods and the biomechanical parameters that have to be considered combining the front-end aggressiveness with the crash test dummies damages. Moreover, many car and system manufacturers are studying new pedestrian protection systems as the active hood that raises instantly when a pedestrian is hit: a sensor system placed in the vehicle’s front bumper sends a signal a two steel pistons below which lift the rear part of the hood making the pedestrian’s head hit a deformable and flexible surface instead of a hard and rigid one. These systems will help car manufacturers to meet the new EU test requirements that the European car manufacturers accepted in 2001 and that will become effective in July 2005. This paper describes an activity on car-to-pedestrian impact carried on by the Universita` degli Studi di Firenze in co-operation with Centro Ricerche FIAT. This activity concerns the study of legform FEM model for LS-Dyna software and the numeric simulation of a sensor system placed in the vehicle’s front bumper. The sensors are piezoelectric stripes stuck on the bumper according to opportune geometries. These sensors were characterised through experimental analysis changing deflection and impact speed; the relationship between the numeric parameters and the electric signal was determined working on easy tests. It was subsequently simulated the impact between the bumper and a legform FEM model developed by Universita` degli Studi di Firenze working on LS-Dyna software. The legform model respect the structural characteristics required by EEVC WG17 report. The legform model was validated by experimental analysis carried on at Centro Sicurezza FIAT AUTO. Thanks to simulations it has been possible to optimise the position of the sensors on the bumper and also to judge the minimum number of sensors, which can distinguish between the different impacts.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Serving the People in Long Beach, California: Advancing Justice for Southeast Asian Youth through Community University Research Partnerships

2019 ◽  
Vol 16 (1-2) ◽  
pp. 1-34
Author(s):  
R. Varisa Patraporn
Keyword(s):  
Asian American ◽  
Research Work ◽  
Community Based Participatory Research ◽  
Youth Empowerment ◽  
Long Beach ◽  
Structured Interviews ◽  
Research Partnerships ◽  
Community Needs ◽  
The People ◽  
The Impact

Khmer Girl’s in Action is a nonprofit that successfully utilizes community-based participatory research (CBPR) with university partners to create social change for youth in Long Beach, CA. Based on semi-structured interviews and content analysis of news articles, I explore the impact and sustainability of this research work and the research partnerships. Findings highlight impacts such as youth empowerment, heightened awareness around community needs, policy change, and CBPR curriculum improvements in the field as impacts. Sustainability requires integrating research into program funding, utilizing a tailored training curriculum, building on community members prior relationships, and selecting partners that share common goals, levels of commitment, and flexibility. As funders demand more data to justify community needs, understanding more examples of such work in the Asian American community will be useful for informing future partnerships.

Impacto de las tecnologías de la información y las comunicaciones: Una mirada en la Educación Superior

2017 ◽  
Vol 1 (6) ◽  
Author(s):  
Karina Virginia Mero Suárez ◽  
Edwin Joao Merchán Carreño ◽  
Ana Del Rocío Fernández Torres ◽  
Narcisa María Crespo Torres
Keyword(s):  
Higher Education ◽  
Information Technology ◽  
Research Work ◽  
Field Research ◽  
Research Problem ◽  
Research Report ◽  
Educación Superior ◽  
Educational Design ◽  
Educacion Superior ◽  
The Impact

El artículo aborda la necesidad de la creatividad que se impone en la era actual del conocimiento y la importancia que  constituyen las tecnologías como herramientas indispensables en todas las esferas de la vida. En Trabajo toma como campo investigativo los cambios que se llevan a cabo en esta esfera en la Universidad Estatal del Sur de Manabí y la Universidad Técnica de Babahoyo, Ecuador, donde se toman como objeto el proceso de enseñanza aprendizaje en la Educación Superior. El objetivo de la investigación fue comunicar el impacto de las Tecnologías de la Información y las Comunicaciones en las Universidades, donde se hace énfasis en el nuevo rol de los docentes y su nuevo desempeño de facilitadores del aprendizaje en los educandos a través en los nuevos escenarios mediados por las tecnologías. Para el desarrollo exitoso de esta memoria investigativa se   usó como metodología instrumentos que se basaron fundamentalmente en documentos referativos que ayudaron a justificar el problema de investigación, el cual consistía fundamentalmente en el impacto de las nuevos  dispositivos tecnológicos y su utilidad en los centros de altos estudios del país. Se concluyó que las Tecnologías de la Información y Comunicación son herramientas indispensables en la docencia y al mismo tiempo la forma de intervenir en el diseño educativo que nos llevan a explorar nuevos métodos docentes en los escenarios educativos mediados por estas. Se constató además que estas herramientas favorecen satisfactoriamente al proceso si se tiene una buena preparación por parte del docente.   Palabras clave: Herramientas tecnológicas, universidades, formación, docencia universitaria, proceso de enseñanza – aprendizaje Impact of information technology and communications: a look at higher education  Abstract The article states the need of the creativity that prevails in the current era of knowledge and the importance that technologies constitute in all spheres of life. In field research work it takes as changes take place in this area in Southern State University of Manabí and the Technical University of Babahoyo, Ecuador, where they are taken as an object the process of learning in higher education. The aim of the research was to communicate the impact of Information Technology and Communications in the universities, where the emphasis is on the new role of teachers and their new performance of facilitators of learning in students through the new scenarios mediated by technologies. For the successful development of this research report it was used as a methodology instruments based mainly on referative documents that helped to justify the research problem, which consisted mainly of the impact of new technological devices and their use in the centers of higher learning in the country. It was concluded that information technology and communication are indispensable tools in teaching and at the same time how to intervene in the educational design that lead us to explore new teaching methods in educational settings mediated by these. It was further found that these tools successfully promote the process if there is a good preparation by the teacher.

Sign in / Sign up

Export Citation Format

Share Document