Composite materials can be tailored for various properties, but the manufacturing process can be quite lengthy depending on the complexity of the final product. Instead, we focused our attention on the relatively new technology of additive manufacturing (3D printing) that can produce complex geometries for a limited number of samples. Due to the weak bond between successive printed layers, these objects will have weaker mechanical properties in relation to cast or sintered materials. Thus, the orientation of the printed layers can make a huge difference in the behavior of the products. In this paper, a 3D printed composite made from bronze-filled PLA is mechanically characterized in order to be used as a substitute for sintered compacted bronze products for compression loads. Thus, cylindrical samples grown with the base horizontally and vertically were subjected to compression loads to determine their stress-strain curves at room temperature as well as in the glass transition region. Due to a lack of published research in this area, this study offers an insight into the usability of bronze-filled PLA for gaskets or other objects subjected to compression loads.

Today, reduction of industrial noise is a widely used concept for improving the life standard in vicinity of industrial and residential mixed areas. The human ear has a very poor auditory acuity in perceiving sounds produced by sound pressure variations in the very low frequencies or very high frequency range. Noise is, in general interpretation, disturbing sound, annoying or even dangerous, although this perception is subjective. There are at least two kinds of people, one that "adapted" psychological noise and learned to work with it and another which gradually became sensitive to noise. In the current situation of industrial development, and housing, many locations of manufacturing facilities are near residential areas, so it is very important to realize noise levels monitoring. Legislation provides for annual measurements of noise levels to limit industrial properties. This paper describes the monitoring, over a period of several years, the noise sources within a company at the limits of Timisoara.

The interaction between wheel and rail is the main source of noise in a tram that moving on the rolling track. Wheel and rail irregularities are the causes that initiate dynamic forces and vibrations. Noise is the result of vibrations generated due to defects located on the contact of these surfaces. Rolling noise levels reduction can be achieved by improving contact surface condition, mainly by wheel bogies reshaping

With the ongoing pace of city development and urban population growth, public transportation is the solution for traffic decongestion. The extensive use of cars causing traffic jams, and more serious pollution, more and more people should travel by public transportation means. In this article, we tested and analysed the vibration characteristics of local tramway transportation by using vibration measurement and analysis system.In spite of increasing exposure to vibrations, transportation supervisors do not concern themselves to the health effects of whole-body vibration or hand transmitted vibrations. Exposure to whole-body vibration is a growing concern in industry, traffic and in other branches of the economy. This harmful physical factor endangers human health not only at work but also in everyday life: in public transportation.The paper concerns with the vulnerability of the human body to vibrations transmitted from trams. The accelerations of the vibrations were measured on the axes (x-, y- and z-axes), and these values were compared to the ones from standards for acceptable human exposure to whole-body vibration.

No abstract