Jarosław Bednarz

Model Based SHM - Rotating Machinery Application

The paper presents application of the model based diagnostic method for early detection of faults in rotating machinery. The applicability of modal model identification techniques for structural health monitoring of rotating machinery for linear and nonlinear cases is presented. The method based on both operational and experimental (with specially designed active experiment) is discussed. The approach including mapping of nonlinear system to time varying linear one is employed. The theoretical formulation of the method and experimental verification on laboratory rig is shown.

Application of finite elements method in the design of road located in the densely built - up residential area

Nowadays, many of the designed roads are located through the densely built-up residential areas, and even the areas where there are historic buildings. Therefore, already at the stage of preliminary road design one should take into account the effects of vibration wave propagation caused by movement of vehicles on buildings located in the immediate vicinity of designed road. One of the methods that can be used to determine the dynamic effects of designed road for residential buildings is the finite element method. This paper presents an application of the finite element method for the estimation of the dynamic interaction of designed road located in the centre of a major city in the nearby residential buildings. Finite element method was used to model the land and buildings located near the designed road. In the process of land modelling the geological studies of ground and measurements of soil vibrations caused by the vibratory road roller rides conducted by the authors were used. Thus, it was possible to tune the developed finite element model. Proposed in this paper method of analysis of ground vibrations reduce the time needed to design a vibration isolating elements that will protect people and buildings from the destructive effects of vibration caused by vehicles movement the designed road. The work was carried out in a research project 4875/B/TO2/2010/38 financed by Ministry of Science and Higher Education.

Adjustment of a Feedwater Heater Model in Bi-stationary Load Conditions

Work related to the tuning of the first-principle model of a feedwater heater operating in a coal-fired power unit is presented. The objectives of this work is to find the most efficient and accurate process to tune the model parameters i.e. heat transfer coefficients under bi-stationary load conditions. The model variables (e.g. variability of the power rate of energy exchange) and estimated pa-rameter values were used to formulate key performance indicators intended for a model-driven diagnostics approach. The computational process was organized in an iterative process of updating model parameters and indicators. The validation was successfully performed using operational data from a 225MW coal-fired power unit.

Applicaton of Modal Filtration for Damage Detection of Rotating Shaft

The paper describes a modification of the method which uses the modal filtration for damage detection [11] to make it suitable for rotating machinery. Authors have formulated a diagnostic procedure which is based on the output only data measured during object operation. The measurement can be performed both by accelerometers placed on the shaft bearing cages and directly on the shaft with use of the laser vibrometer. The procedure was verified on the experimental data. For the experimental verification authors have used the laboratory stand which allows simulation of different faults.