The paper presents theoretical and experimental analyses of a possible effect of the short-circuit forces on the transformer winding. The first part of the paper is focused on creation and activity of the radial and axial forces during a short circuit. It shows dimensions, direction and − of course − the resulting mechanical stress. The presented equation shows basic dependencies of these mechanical forces created in the transformer winding. Finally, the paper presents experimental methods of diagnosing and analysing the effects of short-circuit forces on the transformer winding.
Welding strength is very important in safe use of polypropylene sheets. The determination of welding parameters and design of the welding tool has an impact on the weld strength. The welding parameters can be determined experimentally. In this study, Charpy impact test is used to determine suitable welding parameters in welding of polypropylene sheets with FSW method. At the same time, the weld zone microstructure is examined and Shore hardness measurements are made. The impact tests were performed on samples cut from the welded sheets. The impact tests values and hardness values were presented graphically. According to the test results, some welded parts behaved similar to the matrix material. In some welding parameters, Charpy impact test values were obtained close to values of the main materials. The suitable welding parameters were determined for polypropylene sheets welding.
Rubberized concrete is made up of scrap tyre rubbers where the fine aggregate is partially replaced by it, as the waste rubber is being a threat to the environment. It is estimated that only 4% of the waste tyre is used in the application of civil engineering and also there is shortage of fine aggregates. The primary objective of this study is to investigate the preliminary concrete properties of M25 and M30 concretes. The fine aggregate is replaced by pre-treated crumb rubber with 10, 15 and 20 % of total weight. Various tests are conducted on the rubberized concrete specimens such as compressive strength, split tensile strength, flexural strength and slump test. The investigation is carried out to determine the impact load behavior of hybrid rubberized composite slabs. In addition 0%, 1%, 1.5%, and 2% of replacement of rubber fibers for total weight of coarse aggregate is also made. The specimen of size 300 mm x 300 mm x 50 mm thickness is subjected to drop hammer test to find its performance against the impact loads. The number of blows for the first crack and complete failure of slab was found and the characteristics were studied.