The aim of the study is the tribological analysis of the crane drum brakes. A theoretical analysis of the wear processes for brake lining was performed and the coefficient of friction under tribological conditions was determined experimentally simulating the operating conditions for three types of brakes. The theoretical study of the wear was oriented towards of determining the lifetime of the brake lining. In the experimental determination of the coefficient of friction, the following parameters were taken into account: the contact pressure between the shoe and the drum; the initial speed of the brake drum; the humidity of the working environment; and the temperature of the drum-brake lining friction surfaces. After performing the experiments, a statistical analysis was conducted, that shows the amount the coefficient of friction is influenced by the previously mentioned parameters: the highest weight was humidity with a value of 35.58%, followed by temperature with a percentage of 23.95%, velocity with 4.54%, and lastly pressure with 4.19%. Furthermore, the equation that expresses the dependence between the coefficient of friction and the parameters is determined. We consider that the results obtained are important for brake manufacturers in order to improve braking efficiency and the safety of overhead cranes.

This study investigates the utilization of barrel end-mills in machining titanium alloys for aerospace applications. It involves a comprehensive review of the relevant literature and a preliminary experimental investigation, incorporating the influence of measurement direction on surface roughness and the behavior of cutting forces. The primary objective is to assess the performance and efficiency of these end-mills when machining challenging materials and to identify optimal cutting strategies. This paper emphasizes the significance of titanium alloys in the aerospace sector, due to their exceptional mechanical properties, and the problems encountered in their processing. It also highlights the advantages of barrel end-mills, such as enhanced accessibility and superior surface finish. Through a combination of literature review, practical experimentation under controlled conditions, and statistical analysis, this study investigates the surface roughness of the Ti-6Al-4V titanium alloy, confirming a significant difference between longitudinal and transverse roughness. The preliminary experiment revealed that the average values of longitudinal and transverse roughness were 0.237 µm and 0.263 µm, respectively. The coefficients of variation indicated a greater variation in longitudinal roughness (19.79%) compared to transverse roughness (18.61%). This study’s conclusions provide a solid foundation for future research into machining titanium alloys with barrel end-mills, contributing to the optimization of manufacturing processes and the enhancement of aerospace component performance.

MATEC Web of Conferences, open access proceedings in Materials science, Engineering and Chemistry

The regular cleaning of the materials deposed in sewer networks is realized, especially with equipment that uses high pressure water jets. The functioning of this equipment is dependent on certain process parameters that can vary, causing variations of the impact forces. The impact force directly affects the cleaning of sewer systems. In order to determine the influence of the process parameters on the impact forces produced by water jets the method of research used is the experiment. The research methods used is that Taguchi design and full factorial design. For the experimental determination of the impact forces a stand for generating water jets and a device for measuring the forces of impact are used. The processing of data is carried out using the Software Minitab 17.

MATEC Web of Conferences, open access proceedings in Materials science, Engineering and Chemistry