This paper presents the study of the impact of vibration induced by the movement of the railway rolling stock on the Forum Gdańsk structure. This object is currently under construction and is located over the railway tracks in the vicinity of the Gdańsk Główny and Gdańsk Śródmieście railway stations. The analysis covers the influence of vibrations on the structure itself and on the people within. The in situ measurements on existing parts of the structure allow us to determine environmental excitations used for validation and verification of the derived FEM model. The numerical calculations made the estimates of the vibration amplitudes propagating throughout the whole structure possible.
Numerical analysis of the tensioning cables anchorage zone of a bridge superstructure is presented in this paper. It aims to identify why severe concrete cracking occurs during the tensioning process in the vicinity of anchor heads. In order to simulate the tensioning, among others, a so-called local numerical model of a section of the bridge superstructure was created in the Abaqus Finite Element Method (FEM) environment. The model contains all the important elements of the analyzed section of the concrete bridge superstructure, namely concrete, reinforcement and the anchoring system. FEM analyses are performed with the inclusion of both material and geometric nonlinearities. Concrete Damage Plasticity (CDP) constitutive relation from Abaqus is used to describe nonlinear concrete behaviour, which enables analysis of concrete damage and crack propagation. These numerical FEM results are then compared with actual crack patterns, which have been spotted and inventoried at the bridge construction site.
The problems connected to developing inductive power transfer IPT systems in aspects of high efficiency and suppression of electromagnetic field (EMF) emission are discussed. It is shown how important it is to compensate for large leakage impedance of IPT coils (air transformer) to improve efficiency of high power transfer. Such compensation circuits operating with resonant frequencies at soft switching conditions additionally allow for reduction of switching losses in power semiconductor devices of converters. The consideration has been illustrated and verified by experimental results measured on two different test stands (50 kW with planar coils and with two 12 kW receiver coils) built in a laboratory of the Łukasiewicz Research Network – Electrotechnical Institute.