The paper describes the wear performance of zinc-aluminium ZA27 alloy, reinforced with silicon-carbide (SiC) and graphite (Gr) particles. The compo-casting technique produced the composite samples. The tested samples were: ZA27 alloy, ZA27/5%SiC composite, and ZA27/5%SiC/3%Gr hybrid composite. A block-on-disc tribometer was used during wear tests under the dry sliding conditions by varying the normal loads and sliding speeds. The sliding distance was constant during tests. The microstructure of the worn surfaces of the tested materials was analysed using the scanning electronic microscope (SEM) and the energy dispersive spectrometry (EDS).

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In practice, structures of pallet racks are characterized by very wide options of beam-to-column connections. The up to date part of the standard Eurocode 3 considers details for the design of connections. However, experimental determination of the joint properties in steel pallet racks is the most reliable process, since it takes into account an inability to develop a general analytical model for the design of these connections. In this paper, a test procedure for the behavior of beam-to-column connections is presented and the results are analyzed according to the procedure defined in the relevant design codes. With aim to avoid expensive experiments to determine structural properties of different types of connections, a polynomial model and a corresponding numerical model were developed to be used for simulating the experiment. After verification, the developed analytical and numerical model can be applied for investigation of various combinations of beam-to-column connections.

Crawler travel gear is a type of heavy vehicle propulsion that is commonly found in tanks, excavators, and specialized off-road vehicles. They have an advantage over wheels when it comes to robust vehicle weight distribution over soft terrain, and some disadvantages as well. They can damage paved roads and have complex design so, considering the enormous weight they must carry, their reliability must be determined and verified. The main parts of the assembly are the drive wheels, which move the crawler, and the supporting structure that holds four-wheel bogies and two-wheel bogies. In this paper, we present a methodology for FEM analysis of parts of an eight-wheel bogie according to DIN 22261-2 standard.

The composites samples based on ZA27 alloy were subjected to tribological tests and the observed results are presented in this paper. The samples (ZA27/5%SiC and ZA27/5%SiC/5%Gr) were obtained by compo-casting technique. Their wear behaviour was compared to the base alloy. The wear tests were done by using a block-on-disc tribometer under lubricated sliding conditions. Tribological investigation were conducted for three normal loads (40 N, 80 N, and 120 N), three sliding speeds (0.25 m/s, 0.5 m/s, and 1 m/s), and sliding distance of 1200 m. The tested materials were analysed by the scanning electronic microscope (SEM) and the energy dispersive spectrometry (EDS). The presence of oil lubricant improved the wear resistance and friction behaviour of both composites and base alloy. The tested composites show much higher wear resistance than the corresponding matrix material. It was established that the ZA27/5%SiC/5%Gr hybrid composite has best tribological properties.