This article presents the methodology, description, and results of experimental studies aimed at determining the impact of the copper concentration in a carbon–metal composite contact strip on the maximum temperature of the copper contact wire during a contact event when used for operation in the railway industry in Europe. Based on these tests, we determined the minimum percentage of copper that is required for the composite to meet the normative requirements for current loads. In addition to experimental research, a 3D FEM numerical model was also developed in which the contact strip and contact wire geometry were mapped, along with imposed loads resulting from the test for current loads mentioned above. Fifteen simulation variants were carried out for the established model, where the value of the thermal conductivity coefficient and the specific heat coefficient were varied. On this basis, we analyzed the sensitivity of thermal coefficients to the contact wire temperature and determined the minimum conductivity coefficient value, which allowed the maximum copper contact wire temperature of 120 °C to be obtained during the verification tests.

The article presents an analysis of the possibility of using a smartphone for sound recording and analysis in relation to reference measurements carried out with laboratory equipment. The scope of the possibility of using recordings by non-calibrated noise measurement (smartphones) was presented,...

The paper presents the results of investigations of the effect of current heating on the microstructure and properties of copper profile contact wires used in railway traction networks. The aim of the study was to determine the effect of the contact wire temperature rising as a result of current heating on the occurrence of permanent changes in material characteristics. The tests were conducted in laboratory conditions through controlled heating of samples with a current of approx. 1500–1600 A, reaching temperatures of up to approx. 280 °C. It was found that in the temperature range of 120–200 °C, changes in the mechanical properties of the material were insignificant, while above 200 °C, a marked decrease in microhardness and a reduction in the indentation modulus were observed. The results obtained indicate that long-term current load leading to an increase in the temperature of the contact wire may cause deterioration of the mechanical properties of the material, its increased susceptibility to permanent deformation and an increased risk of damage to the traction network, which has a direct impact on the durability of contact wires and the maintenance costs of the rail transport infrastructure.