Estimating Energy Absorbing Performance of Motorcycle Safety Helmet

2014 ◽  
Vol 663 ◽  
pp. 574-578 ◽  
Author(s):  
Hamzah Azhar ◽  
Aqbal Hafeez Ariffin ◽  
Solah Mohd Syazwan ◽  
Shaw Voon Wong
Keyword(s):  
Impact Test ◽  
Head Injuries ◽  
Experimental Tests ◽  
Motorcycle Safety ◽  
The Public ◽  
Centre Of Gravity ◽  
Management Capability ◽  
Energy Absorbing ◽  
Gravity Acceleration ◽  
The Impact

Motorcyclists’ fatalities are overrepresented in the national statistics for years and the figure is predicted to rise further into the year 2020. In details, head injuries have contributed approximately 60% to the records, despite the use of safety helmets. New helmets performance has been well studied and widely accepted to reduce the head injury risks to motorcyclists by way of maximizing crash energy absorption. However in-service helmets energy management capability and information are limited. Therefore, this work attempts to further explore the knowledge and seek clarification of in-service helmet energy absorbing performance by performing experimental tests relative to standards protocols. A set of in-service helmets were collected from the public through an exchange basis and impact-tested twice per sites, at 4 sites, in accordance to MS1:1996 test protocols. The main data obtained was headform centre of gravity acceleration values, in terms of g. The results indicated that energy absorbing performances of most in-service helmets were able to meet standard requirements, regardless of their service ages. A few samples, however, demonstrated out of tolerance performances especially in the successive impact test at the same sites. Appearance of microcrack in the impact foam may have contributed to these values.

Airbag head restraint system

2000 ◽  
Vol 214 (3) ◽  
pp. 229-241 ◽  
Author(s):  
J Latchford ◽  
E. C. Chirwa
Keyword(s):  
Injury Severity ◽  
Head Injuries ◽  
Experimental Tests ◽  
Restraint System ◽  
Head Restraint ◽  
Current Test ◽  
Severity Of Injury ◽  
Good Potential ◽  
New Criterion ◽  
The Impact

The function of a head restraint system is to prevent injurious hyperextension of the occupant's neck in the event of a road vehicle rear end impact, and thus it must have adequate stiffness to limit the movement of the head relative to the torso. Also, it should absorb the kinetic energy progressively so that the head does not sustain any injury and does not roll on the cushion. Practically, a well-designed head restraint will have an optimum balance of these features and thereby offer adequate protection for both the head and the neck. This paper presents some pioneering thinking on head restraint design and develops criteria for qualifying the systems. It presents an airbag head restraint system that has optimum stiffness and good potential for reducing head and neck injuries suffered through rear end collisions. It also presents the results of experimental tests conducted on this novel airbag head restraint system and on several randomly selected existing head restraints. Furthermore, analysis of energy absorption capabilities, head injury criterion (HIC) values and a new criterion, called the equivalent impact power criterion (EIPC), is developed in order to quantify the relation between the rate at which energy is imparted to the head during the impact cycle and injury severity. Current test results show that, the lower the EIPC, the better is the head restraint system and the less is the risk of whiplash and head injuries. Moreover, the work has quantified a number of variables, including the optimum stiffness, as the factors governing the severity of injury to the occupant in a rear impact scenario.

scholarly journals Народна школа грамоти в таборі полонених українців Вецляр, Німеччина (вересень 1915 – березень 1917 рр.): короткий нарис історії створення та діяльності.

2021 ◽  
pp. 81-87
Author(s):  
Ігор Володимирович Срібняк
Keyword(s):  
Public School ◽  
Cumulative Effect ◽  
Opportunity To Learn ◽  
Prisoners Of War ◽  
National Character ◽  
Teaching Staff ◽  
The Public ◽  
Centre Of Gravity ◽  
Teacher Student ◽  
The Impact

The article analyzes the specifics of the functioning of the public school in the Wetzlar Camp of Ukrainian prisoners of war who served in the tsarist army. The authors also identify the impact of education on the prisoners. Although the school was an effective tool of the Ukrainization processes, its influence was limited by strong anti-Ukrainian obstruction by the Black Hundred groups’ members and the Little Russians during September 1915 – October 1916. They were kept in the camp for many months. Nevertheless, the teaching staff of the school did not stop their work, contributing into the formation of national consciousness of their Ukrainian students. In the autumn of 1916, the efforts of the local Ukrainian clubs and institutions (including the public school) brought about a cumulative effect – most campers had adhered pro-Ukrainian views and begun actively participate in the activity of camp cultural and educational centres. This way the public school became a kind of «centre of gravity» throughout the camp and the number of its students grew steadily. It happened because the prisoners realized the ultimate need for their own education. They wanted to get rid of their illiteracy and acquired additional primary knowledge from various subjects offered to them by the school. The teachers staff were the civilian members of the Educational Department of the “Union for the Liberation of Ukraine”. Thanks to them, the prisoners had the opportunity to learn Ukrainian literature, as well as get some knowledge in history and geography of Ukraine, arithmetic and science. Thus, because of the public school, the prisoners not only acquired literacy, got writing and grounding in mathematics, but they also broaden their minds.  The irreversible changes in their national character happened due to the education and consistent patriotic position of the teachers. After visiting school, most of students were already inextricably linked to Ukraine, ready to share their knowledge to affirm national ideals among the Ukrainians. Key words: Ukrainians – prisoners of war, public school, alphabet, teacher, student, Wetzlar camp, Germany.

Bulletproof and Noise-Reducing Guards in Lightweight Design for Woodworking Machines

2014 ◽  
Vol 907 ◽  
pp. 41-54
Author(s):  
Uwe Heisel ◽  
Vincenzo Forcillo
Keyword(s):  
Sheet Metal ◽  
Machine Tools ◽  
Impact Test ◽  
Lightweight Design ◽  
Experimental Tests ◽  
Sound Emission ◽  
Retention Capacity ◽  
Fem Model ◽  
The Moment ◽  
The Impact

At present, guards on woodworking machine tools have to undergo an impact test with a 100 g projectile and an impact speed of 70 m/s to protect the operator against breaking tools. At the moment, only sheet metal housings and plastic elements of polycarbonate as well as particular safety curtain systems meet these requirements regarding the retention capacity of machine enclosures for woodworking centres according to EN 848-3. In context of this work, a machine enclosure made out of lightweight materials was developed as alternative to the conventional sheet metal housings. A solution for safety curtains that passes easy over the workpieces without damaging the edges was also worked out. With regard to rigid guards, many different kinds of material combinations were examined concerning retention capacity and acoustic behaviour. In addition to the experimental tests, a FEM model was developed representing the impact behaviour of the composite based. Finally, a lightweight enclosure prototype was designed and examined with regard to the retention capacity at critical spots and of sound emission.

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]

Experimental Study of Corrugated Tubes Under Lateral Loading

2010 ◽  
Author(s):  
A. Eyvazian ◽  
M. Shakeri ◽  
M. Zarei Mahmoudabadi
Keyword(s):  
Experimental Tests ◽  
Absorption Characteristic ◽  
Lateral Compression ◽  
Lateral Direction ◽  
Static Tests ◽  
Crushing Force ◽  
Innovative Solution ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
The Impact

The protection of structures under impact loading often necessitates the need for energy absorbers; devices designed to absorb the impact energy in a controlled manner and hence, protect the structure under consideration. Thin-walled tubes are widely used as energy absorbers in various vehicles and moving parts. The objective of the present study is to investigate the energy absorption characteristic of tubes with corrugations in different geometries, in lateral direction. In order to produce corrugations, an innovative solution is introduced. Corrugations can be very easily generated on the surface of cylindrical aluminum tubes by stamping method. Corrugations with different wavelengths and amplitudes can be produced by this method. Experimental tests are conducted to study the effect of changing corrugation geometry (type and amplitude). Quasi-static tests are carried out whose results for lateral compression show that tubes with corrugation have a higher mean crushing force and this force is directly proportional to number of corrugations and their amplitude. Moreover, it is observed that corrugated tubes can absorb approximately four times more energy than tubes without corrugations, in the same size and weight. Finally, considering the experimental tests, corrugated tubes are shown to be more effective in lateral direction as an energy absorber, and they also exhibit desirable force-deflection responses which are important in the design of energy absorbing devices.

Numerical and Experimental Study of Radial Impact Test of an Aluminum Wheel: Towards Industry 4.0 Virtual Process Assessment

2017 ◽  
Author(s):  
F. Ballo ◽  
R. Frizzi ◽  
M. Gobbi ◽  
G. Mastinu ◽  
G. Previati ◽  
...  
Keyword(s):  
Experimental Study ◽  
Impact Test ◽  
Experimental Tests ◽  
Actual Structure ◽  
Material Inhomogeneity ◽  
Critical Areas ◽  
Wheel Rim ◽  
Explicit Solver ◽  
The Impact ◽  
Virtual Process

The paper deals with a numerical and experimental study of the radial impact test of an automotive aluminum wheel. The final aim is the confident virtual execution of the test in view of a pervasive digitalization of the aluminum wheel production process. A finite element based model is developed. The model includes tire, wheel, striker and supporting structure. The actual structure of the tire is modeled. Tire damping is included through a Rayleigh model. The Rayleigh’s parameters are experimentally identified. The wheel material inhomogeneity is taken into account by assigning different stress/strain curves to wheel rim and spokes. The material curves have been experimentally measured considering specimens extracted from three different regions of actual wheels. The dynamic impact test is simulated by means of a nonlinear explicit solver. Experimental tests on an impact test bench have been realized to validate the developed model. Accelerations during the impact test are measured on the striker. The impact force at the striker is measured by two load cells. The deformation of the wheel is measured by strain gauges located at the most critical areas of the wheel rim and spokes. A good agreement between measured and simulated quantities is obtained. An accurate model of the impact test is now available including a digital representation of the qualification process of aluminum wheels.

Evaluation of the impact of public investment programs on social and economic performance of territories

2019 ◽  
pp. 109-123
Author(s):  
I. E. Limonov ◽  
M. V. Nesena
Keyword(s):  
Bayesian Modeling ◽  
Positive Impact ◽  
Public Investment ◽  
Difference In Differences ◽  
The Public ◽  
Export Activity ◽  
Regional Investment ◽  
The Difference ◽  
The Impact ◽  
Development Institution

The purpose of this study is to evaluate the impact of public investment programs on the socio-economic development of territories. As a case, the federal target programs for the development of regions and investment programs of the financial development institution — Vnesheconombank, designed to solve the problems of regional development are considered. The impact of the public interventions were evaluated by the “difference in differences” method using Bayesian modeling. The results of the evaluation suggest the positive impact of federal target programs on the total factor productivity of regions and on innovation; and that regional investment programs of Vnesheconombank are improving the export activity. All of the investments considered are likely to have contributed to the reduction of unemployment, but their implementation has been accompanied by an increase in social inequality.

Use of thermomechanical pulp fibers from waste woods for making eco-friendly cushioning material

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 15-21 ◽  
Author(s):  
JI-YOUNG LEE ◽  
CHUL-HWAN KIM ◽  
JEONG-MIN SEO ◽  
HO-KYUNG CHUNG ◽  
KYUNG-KIL BACK ◽  
...  
Keyword(s):  
Impact Test ◽  
Product Distribution ◽  
Expanded Polystyrene ◽  
Thermomechanical Pulp ◽  
Fiber Structure ◽  
Pulp Fibers ◽  
Cationic Starch ◽  
Thermal Insulating ◽  
Surface Sizing ◽  
The Impact

Eco-friendly cushioning materials were made with thermomechanical pulps (TMPs) from waste woods collected from local mountains in Korea, using a suction-forming method without physical pressing. The TMP cushions had superior shock-absorbing performance, with lower elastic moduli than expanded polystyrene (EPS) or molded pulp. Even though the TMP cushions made using various suction times had many voids in their inner fiber structure, their apparent densities were a little higher than that of EPS and much lower than that of molded pulp. The addition of cationic starch contributed to an increase in the elastic modulus of the TMP cushions without increasing the apparent density, an effect which was different from that of surface sizing with starch. In the impact test, the TMP cushions showed a more ductile pattern than the brittle EPS. The porosity of the TMP cushion was a little less than that of EPS and much greater than that of molded pulp. The porous structure of the TMP cushions contributed to their excellent thermal insulating capacity, which was equivalent to that of EPS. In summary, the TMP packing cushions showed great potential for surviving external impacts during product distribution.

#INCLUSION – THE IMPACT OF SOCIAL MEDIA COMMUNICATION ON THE LEGITIMACY OF ARMED FORCES

2019 ◽  
pp. 43-60
Author(s):  
EVA MOEHLECKE DE BASEGGIO ◽  
OLIVIA SCHNEIDER ◽  
TIBOR SZVIRCSEV TRESCH
Keyword(s):  
Social Media ◽  
Political Communication ◽  
Structural Equation ◽  
Armed Forces ◽  
Equation Model ◽  
Media Communication ◽  
The Public ◽  
Political Legitimation ◽  
Social Media Communication ◽  
The Impact

The Swiss Armed Forces (SAF), as part of a democratic system, depends on legitimacy. Democracy, legitimacy and the public are closely connected. In the public sphere the SAF need to be visible; it is where they are controlled and legitimated by the citizens, as part of a deliberative discussion in which political decisions are communicatively negotiated. Considering this, the meaning of political communication, including the SAF’s communication, becomes obvious as it forms the most important basis for political legitimation processes. Social media provide a new way for the SAF to communicate and interact directly with the population. The SAF’s social media communication potentially brings it closer to the people and engages them in a dialogue. The SAF can become more transparent and social media communication may increase its reputation and legitimacy. To measure the effects of social media communication, a survey of the Swiss internet population was conducted. Based on this data, a structural equation model was defined, the effects of which substantiate the assumption that the SAF benefits from being on social media in terms of broadening its reach and increasing legitimacy values.

The Impact of the Public Expenditure Cuts Policy on the Labor Market in Vietnam

2012 ◽  
pp. 22-46
Author(s):  
Huong Nguyen Thi Lan ◽  
Toan Pham Ngoc
Keyword(s):  
Labor Market ◽  
Computable General Equilibrium ◽  
Impact Evaluation ◽  
Public Expenditure ◽  
Computable General Equilibrium Model ◽  
Living Standard ◽  
Input Output ◽  
Policy Makers ◽  
The Public ◽  
The Impact

The purpose of this study is to evaluate the impact of public expenditure cuts on employment and income to support policies for the development of the labor mar- ket. Impact evaluation is of interest for policy makers as well as researchers. This paper presents a method – that is based on a Computable General Equilibrium model – to analyse the impact of the public expenditure cuts policy on employment and income in industries and occupations in Vietnam using macro data, the Input output table, 2006, 2008 and the 2010 Vietnam Household Living Standard Survey.

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