ABSTRACT
A prerequisite for continuous transport systems' operation is their digital transformation, which interprets operating conditions based on the availability of a wide range of data and information in the form of measured quantities that can be obtained, for example, by experimental measurement. To implement digital transformation in continuous transport systems, it is necessary to examine and analyze the informative value of individual measured quantities in detail. Research in this area must focus on identifying addressable quantities with a clear, informative value. Such an approach enables the monitoring of continuous transport systems operation and performance of operational diagnostics, the objective of which should be identifying undesirable operating conditions. Within this paper, research will be presented aiming to verify the hypothesis that, based on a measurement of selected parameters, it is possible to identify belt mistracking in a continuous transport system. Belt mistracking is an undesirable condition that can cause a conveyor belt to converge and thus seriously turn off an entire transport system. The research results confirmed the established hypothesis. Based on this, an evaluation algorithm was created for on-time evaluation. The proposed algorithm is also suitable for the needs of a digital twin of a continuous transport system.
ABSTRACT
Gyroid structures are among the most widely used three-dimensional elements produced by various additive manufacturing technologies. This paper focuses on a metrological analysis of Flexfill 92A material specimens with a relative density (25 to 85%) using industrial computer tomography. The results show that for a given structure, the best method is to use surface determination with the closure of internal defects in the material. The analysis implies that the smallest deviations of the specimens' external dimensions were achieved with respect to the CAD model at the highest relative densities. The wall thickness shows the smallest percentage change of 0.5685 at 45% relative density and the largest at 25% and 85% relative density. The nominal-actual comparison of manufactured specimens to the CAD model shows the smallest cumulative deviation of 0.209 mm at 90% and 25% relative density, while it slightly increases with increasing relative density. All produced specimens have a smaller material volume than their theoretical volume value, while the percentage change in volume is up to 8.6%. The surface of specimens is larger compared with the theoretical values and the percentage change reaches up to 25.3%. The percentage of pores in the specimens increases with increasing relative density and reaches 6%. The acquired knowledge will be applied in the framework of research focused on the possibilities of using additive manufacturing to produce a skeleton of rubber-textile conveyor belts. This paper presents initial research on the possibility of replacing the carcass of rubber-textile belts with an additive technology use.
ABSTRACT
This article explores the effect of carbon fiber content on the flexural strength of polymer concrete testing samples and compares the damping of polymer concrete and U-shaped steel profiles. The experiments involved and described herein consisted of flexural strength testing according to STN EN 12 390-5 Testing of Hardened Concrete, Part 5: Flexural Strength of Test Samples. The test results were evaluated graphically and by calculations and were further processed in various programs. The experimental results indicated that the highest flexural strength value was obtained by the test samples containing 12% of carbon fibers while culminating at 17.9 MPa. The results showed that the highest increase of flexural strength was caused by the addition of 3% of carbon fibers to the mixture, which increased the flexural strength by 4.2 MPa, or 26.75%. The results indicated that, based on the shape of the regression curve, flexural strength culminated at 13% carbon fiber content. The experimental results demonstrated that the tested polymer concrete test sample had a 6.87 times higher attenuation coefficient than the U-shaped steel profile. The results showed that the polymer concrete test sample No. 4 reduced vibration acceleration deviation by 93.5% in 0.005 sec and the U-shaped steel profile by 32.9%.
ABSTRACT
This article examined the possibility of using CuSn6P claddings in sliding bearing renovation of movable pontoon bridge props. The bronze layer was welded on cylinders of the high-strength steel S355J0WP EN 10155-93, in an inert atmosphere using an automated welding method (gas tungsten arc welding). Pulsed arc welding was used to minimize the effects of heat on the cladding area, while also accounting for the differences in the physical properties of the joined metals. The sliding bearing was created in two layers. The quality of the cladding layer was evaluated by nondestructive and/or destructive tests. The quality of the surface was assessed by visual inspection (visual testing) in accordance with the EN ISO 17637 standard. The quality of the claddings was evaluated by metallographic analysis, performed using light microscopy. The microhardness values of a few weld areas were determined by Vickers tests, performed according to the EN ISO 9015-2 standard. The analyses confirmed that the welding parameters and filler material used resulted in high-quality weld joints with no internal (subsurface) or metallurgical defects.
