Issue 3

 

L. Číhalová* & L. Hynčík

 

ABSTRACT: Recently the virtual finite element human body models are getting important to be used to improve a passive safety of vehicle occupants. The human body models have a significant importance over dummies, since they are able not only to predict injuries but also to model the whole injury mechanism. This enables the detailed analysis of injuries and hence more precise optimization of safety systems. To be able to use the models for this purpose, the objective model of human body needs to be created. Such human body model ROBBY is being developed at University of West Bohemia (UWB) in cooperation with ESI Group. This model is still updated to have more realistic model. The aim of this study was to improve the thoracic part of the human body model by the implementation of created thoracic model to the existing ROBBY model and use the updated model as a tool for safety evaluation. Two types of sled tests were performed to compare the behavior of the updated model ROBBY and cadavers. The first sled test was performed at 30 km/h without airbag and the second one at 50 km/h with airbag. The comparison of the response of the thorax-abdomen complex for the model and cadavers was performed.

KEY WORDS: Sled test, ROBBY model, cadaver, biomechanics, frontal impact

 

 

V. Adamec*, J. Dufek, J. Jedlicka, R. Licbinsky

V. Bencko,

 

ABSTRACT: This presentation introduces the situation of POPs transport emissions in the Czech Republic since 1993 including the prediction for 2010 and 2015 years, determination of emission factors, possibilities of its reduction and legislative framework. From achieved results it is evident that the emissions from the road and railway transport exceed 28 tons in 2005. The naphtalene creates more than 90 % in emissions of vehicles fulfilling EURO I-III limits. The phenanthrene (about 50 % of PAHs) predominates in emissions of older gasoline vehicles that do not fulfil EURO limits, naphtalene content is about 10 %. Total emissions of PCDDs and PCDFs are relatively low in the same context in emissions of mostly older vehicles, manufactured before acceptance of EURO limits. The potential health risks related to human exposure to transport emissions are subject of our present research interest.

 

Keywords: polyaromatic hydrocarbons, polychlorinated bifenyls, polychlorinated dibenzo-dioxines, polychlorinated dibenzo-furanes, emissions, emission factors, air pollution, transport emissions.

 

 

 

 

ABSTRACT: The results of the presented solutions and the developed analytical and design methods will help creating the sufficient theoretical tools for reliable and economic structural design bridges without deflection impairments. The paper reviews the causes of under-estimation of the long-time future deflections. Special attention is directed to prestressing – a procedure to find the optimal arrangement of tendons layout is presented, allowing avoiding the tendons contributing to deflection increases. Developed computer program is freely available and a method of repair procedure and a repair example, as well as recommendations for the design practice are also presented.

KEY WORDS: bridge, creep, deflection, prestressed concrete, shear

 

 

 

P. Řeřicha

 

ABSTRACT: Simple formulas are developed for the mass scale load rating assessment of masonry arch bridges in terms of four geometrical parameters of the bridge. The ultimate load limit state and the repeated load limit state constitute the theoretical background. The formulas are constructed as the least squares best fit to a set of linear and non-linear finite element solutions of a representative selection of the country's bridge stock. The formulas are quadratic in the arch span and linear in the arch rise, arch thickness and fill depth. The method can be used for other countries' masonry arch bridge stock; the data processing programme is portable. The structure of the formulas and the country's bridge stock representation can be adapted to local conditions. Nevertheless, new representations of bridge instances require rather demanding non-linear finite element solutions up to total collapse. This is the most laborious part of the formula’s development.

 

KEY WORDS: Arch bridges, masonry, load rating, limit states, finite element method, semiempiric formulas

 

 

 

 

M. Hönig* &J. Kovanda & J. First

 

ABSTRACT: This study considers the possibility of using the tank as a potential place for a motorcycle airbags.This study is the combination of the efforts of CTU in Prague, HTW Dresden as well as JAWA and DELPHI for the improvement of passive safety of motorcycle riders. The tank shapes are taken into consideration as to their effects on passive safety including their suitability and unsuitablility. A detailed description as to the possibilities of using the software MADYMO as a tool for inital blue-print of any motorcycle airbag if placed on the tank. 

 

KEY WORDS: Passive safety, crash test, airbag for motorcycle, tank deformation, tank shape, computer simulation, use of software MADYMO

 

 

 

M. Moravec

 

K. Pospíšil*

 

ABSTRACT: Surface drainage of road pavements with very low both longitudinal and transversal gradients is subject of special solutions. Drainage grooves rabbeted into the road pavement wearing course are one of them. While costs of this kind of maintenance are not inconsiderable, effectiveness of such solution has not been evaluated independently yet. The paper describes experiments done in the field of the drainage grooves effectiveness and on the base of them specifies limitations of the grooves usage.      

 

KEY WORDS: Surface drainage, drainage groove, rabbet, pavement, wearing course