Computer vision is a frequently used approach in static and dynamic measurements of various mechanical structures. Sometimes, however, conducting a large number of experiments is time-consuming and may require significant financial and human resources. On the contrary, the authors propose a simulation approach for performing experiments to synthetically generate vision data. Synthetic images of mechanical structures subjected to loads are generated in the following way. The finite element method is adopted to compute deformations of the studied structure, and next, the Blender graphics program is used to render images presenting that structure. As a result of the proposed approach, it is possible to obtain synthetic images that reliably reflect static and dynamic experiments. This paper presents the results of the application of the proposed approach in the analysis of a complex-shaped structure for which experimental validation was carried out. In addition, the second example of the process of 3D reconstruction of the examined structure (in a multicamera system) is provided. The results for the structure with damage (cantilever beam) are also presented. The obtained results allow concluding that the proposed approach reliably imitates the images captured during real experiments. In addition, the method can become a tool supporting the vision system configuration process before conducting final experimental research.

The paper discusses a perspective of the usage of various types of smart materials to enhance the operational properties of Gas Foil Bearings. The authors, referring to the current investigation on thermomechanical characteristics of the above-mentioned bearing type, have focused on the concept of using Shape Memory Alloys, Piezoelectric Transducers, Thermoelectric Modules and Thermocouples to improve both mechanical and thermal behavior of the bearings. Based on the available literature and the authors’ experience, the present work provides an overview of the known and perspective applications of smart materials to Gas Foil Bearings. In particular, a discussion on their capabilities, limitations and effectiveness is conducted, taking into account the unique characteristics and requirements of the studied type of bearings.

Maintenance of adequate thermal properties is critical for correct operation of a gas foil bearing. In this work, the authors present the results of the experimentally conducted thermal characterization of a prototype installation of the bearing. A novel method of temperature identification, based on integrated thermocouples readings, has been employed to determine the thermal properties of the specialized sensing top foil mounted in the tested bearing. Two measurement campaigns have been subsequently completed, applying freely-suspended and two-node support configurations, to gather complementary knowledge regarding the bearing’s operation. Apart from the rotational speed and temperature field measurements, the authors have also studied the friction torque and the shaft’s journal trajectories based on its radial displacements. The temporal courses for the above-mentioned quantities have enabled inference on the effects present during run-up, run-out and stable state operation at a constant speed. As confirmed, the applied distribution of the integrated sensors allows for temperature readings on the entire outer surface of the foil, and therefore, provides useful data for the bearing characterization. The work is concluded with presentation of the recommended directions regarding future improvements of the proposed measurement technique and more comprehensive study of the bearing’s characteristics.

The article presents simulation results on the active control strategy for a railway pantograph to improve contact quality in pantograph–catenary interface. Three different approaches were investigated: nominal torque tuning, torque active control and combination of them—combined control approach. The first control scenario minimizes the pantograph nominal uplift force exerted on the catenary. The second approach is based on active pantograph toque control, employing the proportional–integral–derivative controller, to compensate actual contact force error. The last control scenario links the above-mentioned approaches. Promising results are obtained employing the co-simulation environment recently presented by the authors.

Modern approaches dedicated to controlling the operation of gas foil bearings require advanced measurement techniques to comprehensively investigate the bearings’ thermal and thermomechanical properties. Their successful long-term maintenance with constant operational characteristics may be feasible only when the allowed thermal and mechanical regimes are rigorously kept. Hence, an adequate acquisition of experimental readings for the critical physical quantities should be conducted to track the actual condition of the bearing. The above-stated demand has motivated the authors of this present work to perform the thermomechanical characterization of the prototype installation of a gas foil bearing, applying a specialized sensing foil. This so-called top foil is a component of the structural part of the bearing’s supporting layer and composed of a superalloy, Inconel 625. The strain and temperature distributions were identified based on the readings from the strain gauges and integrated thermocouples mounted on the top foil. The measurements’ results were obtained for the experiments that represent the arbitrarily selected operational conditions of the tested bearing. Specifically, the considered measurement scenario relates to the operation at a nominal rotational speed, i.e., during the stable process, as well as to the run-up and run-out stages. The main objectives of the work are: (a) experimental proof for the described functionalities of the designed and manufactured specialized sensing foil that allow for the application of a novel approach to the bearing’s characterization, and (b) qualitative investigation of the relation between the mechanical and thermal properties of the tested bearing, using the measurements conducted with the newly proposed technical solution.

The development of highly efficient and environmentally friendly machines requires the use of new technologies that are created using innovative design solutions and new materials. This also applies to various types of propulsion units, such as gas microturbines or combustion engines. Although these machines have been known for many years, by using new components, it is still possible to improve their performance. This article presents an experimental study conducted on a gas foil bearing using a polymer coating as an anti-friction material. These types of bearings allow for a reduction in friction losses and are not lubricated with conventional lubricants. The dynamic characteristics of the foil bearing structure were determined, which are essential in terms of both rotor dynamics and the entire propulsion system. The research was carried out over a wide range of frequencies, with different loads acting in different directions. Hysteresis loops and vibration orbits were determined. The authors showed that displacements perpendicular to the load in some cases may be relatively large and should not be ignored. The results obtained during the tests can be used to validate numerical models of such bearings, optimize their design and select the structural and anti-friction materials.