The physics of the induction heating is based on coupling of the electromagnetism and heat transfer. The main heat source during induction heating is resistive heating caused by eddy currents in the heated specimen. The geometrical position of the inductors influences the final surface temperature distribution. There are many technological processes which require uniform surface temperature like process of induction hardening. The scope of the article is to show the numerical approach to optimize geometrical dimensions of the induction heating process in order to reach uniform surface temperature on heated specimen.

The purpose of a road vehicle’s friction brakes is to convert a vehicle’s kinetic energy to thermal energy. When doing so, the brakes should not be heated to such temperatures at which their efficiency could be reduced. The objective of the measurements in this article is to assess the ability of passenger brakes’ spare parts, brake discs and brake pads to meet the requirements for brakes. For the experimental measurements, brake discs and brake pads of high, middle and low prices were selected from advertisements intended for a particular vehicle. The measurements were performed via driving test measurements as well as under laboratory conditions. Driving test measurements determined the brake distance and mean fully developed deceleration of the brake components of all three price categories. On the other hand, the dependence between the effort to control the steering and the brake force, as well as the temperature of brake discs during repeated interrupted braking and continuous uninterrupted braking, were determined under laboratory conditions. Attention was also given to prevention against corrosion. The results show a sufficient ability of all the brake pads and brake discs tested to generate braking force under common conditions. However, when using the lowest-priced brake discs and brake pads, a substantial reduction in their efficiency can occur if braking intensively or over a long period.

Thermal imaging is a non-destructive test method that uses an external energy source, such as a halogen lamp or flash lamp, to excite the material under test and measure the resulting temperature distribution. One of the important parameters of lock-in thermography is the number of excitation periods, which is used to calculate a phase image that shows defects or inhomogeneities in the material. The results for multiple periods can be averaged, which leads to noise suppression, but the use of a larger number of periods may cause an increase in noise due to unsynchronization of the camera and the external excitation source or may lead to heating and subsequent damage to the sample. The phase image is the most common way of representing the results of lock-in thermography, but amplitude images and complex images can also be obtained. In this study, eight measurements were performed on different samples using a thermal pulse source (flash lamp and halogen lamp) with a period of 120 s. For each sample, five phase images were calculated using different number of periods, preferably one to five periods. The phase image calculated from one period was used as a reference. To determine the effect of the number of excitation periods on the phase image, the reference phase image for one period was compared with the phase images calculated using multiple periods using the structural similarity index (SSIM) and multi-scale SSIM (MS-SSIM).

Purpose of this paper is to present the magnitude of the impact of roller bearing rings mutual slewing to the process of contact stresses in rolling elements. The roller bearing satisfies prescribed basic static load rating if it is loaded by ...