International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Nowadays hybrid vehicles take increasing share of new road vehicles, but also the electric vehicles have continuous development which is a sign of a serious beginning of new era of their use. The goals of introducing of these vehicles include lowering of the negative impact on the environment and also reducing of their operational costs. Together with the mentioned trends, there are some specifics related to the risks of using this type of vehicles. This paper gives the key elements related to the development of hybrid and electric vehicles with emphasis of the general distinctions in terms of conventional vehicles with internal combustion engines. The paper has focus on risk identification and hazards that can arise from hybrid and electric vehicles, which are specifically related to their technical differences from conventional vehicles with internal combustion engine. Those risks exist when the vehicles are in use, but also even when the vehicle is not in operation. There is also identification of potential risks for the emergency staff when there is accident with these types of vehicles. The paper also addresses the possible harmful events that can happen later or because of improper repairs of the vehicles. Having in mind that the literature sources are quite moderate and in Republic of Macedonia there is none, the conclusion represent an effort to systemize the available knowledge in order to help vehicle users and professionals to mitigate or lower the recognized risks.

A cylinder bundle is a portable assembly which consists of a frame and two or more cylinders, each of a capacity up to 150 l and with a combined capacity of not more than 3000 l, or 1000 l in the case of toxic gases, connected to a manifold by cylinder valves or fittings such that the cylinders are filled, transported and emptied without disassembly. The type approval of the cylinder bundle covers series of tests regarding its structure and its behavior during and after the tests. The research, presented in this paper, is focused on virtual testing, i.e. modeling and simulation of a cylinder bundle drop tests. First, a CAD model of a cylinder bundle which contains five cylinders is built, and then a vertical and rotational drop tests are simulated in virtual environment. The obtained results are analyzed in line with the demands defined in the international standard ISO 10961:2010(E).They could serve as a base for further improvement of the model and point out the possibility for validation of the virtual testing.

The development of high power electronics, improvement of existing and emerging of new battery technologies and optimization of electric motors over the last decade are some of the issues that have raised the interest in electric vehicles. Based solely on tank to wheel analyses, electric vehicles are regarded as zero emission vehicles. Regarding these facts, the research presented in this paper is focused on mixed traffic with different percentage rates of electric vehicles and its environmental influence in urban areas. A model of a mixed traffic stream comprised of conventional and electric vehicles was built upon a microscopic single lane urban traffic simulator.

Through number of parallel simulations of solely conventional and mixed traffic stream and analysis of the results, we have evaluated the influence that certain presence rates of electric vehicles in the mixed traffic stream have on the exhaust emission. The results that we have obtained are constrained by the assumption that the electric energy used by the electric vehicles originates from renewable energy sources.