Due to the types of construction (steel, concrete etc.), the type of excitation (caused by wind, rail and traffic etc.) in the measurement of engineering structures’ vibration different measurement techniques and different data processing techniques are used. The paper presents the comparison of Classical and Operational Modal Analysis on the basis of engineering structures. The results of vibration's measurements of selected engineering structures with the use of different methods of data processing are presented and discussed in the paper. Dynamic measurements of a structure were performed with the use of a multichannel PULSE system, produced by the Brüel & Kjær

The pulsed high power microwave (HPM) technology has been developed worldwide for over 20 years. The sources of HPM pulses are a weapon of mass destruction. They pose danger especially to computer and telecommunications equipment and systems, both the military and civilian ones. This paper presents a survey of literature on electromagnetic wave radiation absorbing and shielding materials to be used in construction. Relevant protective measures should include the shielding of buildings or their parts and the absorption of radiation by building envelopes and their elements. The main focus is on the possibilities of improving the shielding and absorptive properties of common construction materials, such as concrete, mortars and synthetic resins. The survey covers the following groups of materials: carbon-based admixtures, nickel powder, iron powders, ferrites, magnetite and polymers. The final part of the survey is devoted to hybrid foam microwave absorbers in which the shape of the material’s inner structure and that of its surface play a special role.

Despite significant advances in the development of high-resolution digital cameras in the last couple of decades, their potential remains largely unexplored in the context of input-output modal identification. However, these remote sensors could greatly improve the efficacy of experimental dynamic characterisation of civil engineering structures. To this end, this study provides early evidence of the applicability of camera-based vibration monitoring systems in classical experimental modal analysis using an electromechanical shaker. A pseudo-random and sine chirp excitation is applied to a scaled model of a cable-stayed bridge at varying levels of intensity. The performance of vibration monitoring systems, consisting of a consumer-grade digital camera and two image processing algorithms, is analysed relative to that of a system based on accelerometry. A full set of modal parameters is considered in this process, including modal frequency, damping, mass and mode shapes. It is shown that the camera-based vibration monitoring systems can provide high accuracy results, although their effective application requires consideration of a number of issues related to the sensitivity, nature of the excitation force, and signal and image processing. Based on these findings, suggestions for best practice are provided to aid in the implementation of camera-based vibration monitoring systems in experimental modal analysis.

Different methods results of data processing applied to measurements of vibrations machines (pumps P-1, P-2 and P-3) and support structures using different measurements techniques (OMA, EMA, ODS) are presented and discussed in the paper. Dynamics measurements of structures were performed with the use of a multichannel PULSE system, manufactured by the Brüel & Kjær. The main purpose of the dynamical measurements was to establish source of big excitation for P-2. Vibration velocity of pump P-2 gain 7mm/s in case of pump P-2 not working and pump P-3 working. According to the standard ISO 10816-3 it is close to dangerous zone