Applied Engineering Letters

47-53

Authors: V. A. Kalhapure, H.P. Khairnar

The friction pair, disc, and pad in a braking system are in a delicate balance, with the pad being a complex combination of constituents that provides predictable characteristics, including a known and consistent friction level. In this investigation, L25 orthogonal array with arranged control factors is used for the design of experiment. Taguchi design, orthogonal array, S/N ratio and variance analysis (ANOVA) are used to explore the effect of factors like applied load, sliding speed and track or interface diameter on wear rate of brake pad friction material. In dry sliding conditions, wear tests are performed on the pin‐on‐disc tribometer with different load values (25-125 N), sliding speeds (300‐1500 rpm) and track diameter values (40‐120 mm). ANOVA results stated that applied load is the most effective with 48.27 %, track diameter is 25 % and sliding speed is 19.23 % on wear rate of pad friction material. In order to obtain the minimum friction material wear rate, the optimum operating parameters have been identified as applied load is 25 N, sliding speed 1500 rpm and track diameter 60 mm. The computed and experimental values for pad material wear rate are adhere closer to 1.93 % of deviations only.

62-68

Authors: B. Novaković, E. Desnica, Lj. Radovanović, R. Ivetić, L. Đorđević, D. Labović Vukić

The research in this paper aimed to show the importance of axial alignment on the example of maintaining a technical system. In this paper, the importance of alignment is examined on industrial fans. The technical system on which the alignment was performed reached the anticipated bearing life of 23,650 operating hours prescribed by the manufacturer, while the technical system on which the alignment was not performed was exposed to excessive load by a misalignment shaft. As a result, it did not meet the expected technical expectations, and it canceled at 5,400 hours of work. Research has shown that the application of alignment can increase the service life of bearings by 4.38 times on axles on which no alignment has been performed. Implementation of modern maintenance concepts, using appropriate methods of technical diagnostics aim to optimize the operation of industrial systems for a short period of time and with as few downtimes as possible. The authors of the paper presented the method of laser alignment in order to bring the industrial fan system into optimal operation. In addition to laser alignment, the condition of the system was checked by vibro diagnostics, before and after access by laser method. The paper presents all measurements performed with vibration analysis devices as well as a visual display of the state of the system during the laser alignment check of an industrial fan. Misalignment leads to incorrect operation, which in the case of electric motors and fans is most often reflected in damage in the form of distortion of the shaft or damage to the bearings.

80-87

Authors: S. Starcevic, S. Savic, N. Filipovic, A. Milovanovic, M. Djordjevic

The main purpose of this study was to reconstruct 3D aorta models based on a series of 2D CT images of two patients suffering from an aneurysm. After the 3D models had been made, a numerical solution of the problem of the abdominal aortic aneurysm was obtained. The numerical solution incorporated mathematical models of biomechanical systems. Various parameters such as shear stress, pressure, and velocity of fluid through blood vessel could be calculated using these methods. The first part of the paper introduces the abdominal aorta and aneurysm. The second part of this paper describes the process of getting 3D model geometries of the aortic aneurysms. Finally, the results obtained from the models are discussed with the aim of predicting a rupture of an abdominal aortic aneurysm and selecting the right treatment for this disease.