Building constructions and their elements must meet requirements related to stability and strength. These are the conditions that determine the safety of the structure during both construction and operation. Safety assessment is based on diagnostic tests, aimed at checking the quality of the erected objects or locating damage to structural elements that arise during operation. This work focuses on experimental SISO modal analysis of ceramic masonry elements. An experiment was carried out on twenty samples of solid brick (good, and intentionally damaged). From this, it was possible to determine the variability of the obtained measurement results of the vibration characteristics of the masonry element, and, thus, to assess the value of the method used in the given research problem. The aim of this study was to test the effectiveness of assessing the degradation of the tested brick elements based on stabilization diagrams. The research confirmed the usefulness of experimental modal analysis in identifying damage to masonry elements, and it has been implemented in selected brickyards in Poland.

Decisions made today in the automotive industry clearly indicate the inevitable end of the last resort for combustion engines, which were small-capacity engines made in line with the idea of downsizing. Certainly, one of the characteristic features of these engines will be maintaining the same power and torque with fewer cylinders, the best proof of which is the Twin Air technology engine proposed by Fiat. The consequence of this action was incomparably greater vibrations compared to classic, four-cylinder combustion engines. This article presents an analysis of various dynamic states of a small-capacity engine made using downsizing technology.

The construction of the mobile stage is a huge challenge for designers due to a very wide range of variable factors affecting it, such as wind or temperature, the value of which in this case depends on the geographical location. An inherent element of the influence of these factors are the accompanying various, both constant and variable loads. Detailed identification of these loads is extremely important both for the safety of use and the diagnostic possibilities of such a complex mechanical structure.

On-board diagnostics of technical condition of the brake system elements provide control during the inter-control period of operation. The use of ABS requires further development of on-board diagnostic tools based on the development of new diagnostic methods using multilevel structural and effect schemes, primarily in terms of efficiency parameters. Increase of the information content by increasing the number of measured kinematic parameters and improving the algorithms for generating control signals for the brake system actuators showed effectiveness of diagnostics. To implement diagnostics of technical state of the brake system elements on board of a vehicle, a structural diagram of a diagnostic device, which uses telecommunication means of connection with an expert system and a voltage strain gauge in the coupling device of a truck has been proposed. It is advisable to carry out in-depth element-by-element diagnostics under bench conditions, with the maximum possible exclusion of random factors affecting the process. To summarize all information about the state of the vehicle's braking system, it is necessary to use an expert system.

Production cost reduction and constraints on natural resources cause the use of waste materials as substitutes of traditional raw materials to become increasingly important. The dynamic development of sewerage systems and sewage treatment plants leads to increases in the produced sewage sludge. According to the Waste Law, municipal sewage sludge can be used if it is properly stabilized. This process results in significant quantities of fly ash that must be utilized. This paper presents investigation results of partial cement replacement influence by the fly ash from sewage sludge on concrete parameters. The results confirm the possibility of fly ash waste applications as a cement substitute in concrete manufacturing. In the later parts of the publication, a pilot study was conducted using the modal analysis methodology and aimed at checking the hypothesis of whether vibration methods can be used in the assessment of the amount of the admixture used in concrete and the effect it has on concrete properties. This is the first time that vibration tests have been used to determine the diversity of the concrete mix composition and to distinguish the percentage of ash added. There are no studies using modal analysis to distinguish the composition of a concrete mix in the scientific literature. The article shows that the vibration test results show the differentiation of concrete composition and can be further improved as a method for determining the composition of mixtures and for distinguishing their mechanical properties. These are only pilot studies, which, in order to develop the target cognitive inference, should be performed in the future on a significantly enlarged number of the studied samples.

Today, abrasive blasting is experiencing rapid development, due to two important factors. The first one is related to the introduction of the throwing wheel as an element that sets the granular media in motion directing them to the treated surface, while the second factor is related to the production of modern machining media. Together, these factors make blasting one of the most efficient mechanical surface preparation methods. Unfortunately, the high erosiveness of the abrasive stream, so appreciated in the process of preparing the treated surface, also contributes to significant wear of the elements in its immediate vicinity. The undertaken issues focus on the possibilities of classifying various states of the throwing wheel of a rotary machine tool based on the analysis of its dynamic properties.