Tomasz Lipecki

Research on Wind Structure in the Wind Tunnel of Wind Engineering Laboratory of Cracow University of Technology

The paper is devoted to the research of the wind structure in a wind tunnel. The work consists of the measurements of flow velocities with use of the X hot-wire anemometers at different sets of turbulizers, as well as the statistical analysis of the measured signals. Power spectral density functions have been obtained for 45 sets of turbulizers placed at the inflow, then 6 sets related to PSD functions representing real wind characteristics have been selected for further analysis.

Dynamic wind action on façade scaffoldings

The paper presents an approach to evaluation of the dynamic wind action on scaffolding structures. FEM model of the scaffolding was created on the basis of geodetic measurements and verified by in-situ dynamic measurements of vibrations. Wind field, random in space and time, was simulated using Weighted Amplitude Wave Superposition (WAWS) method. Wind forces were applied to the nodes of the FEM model in every connection between stands and decks in outer plane of the scaffolding. Direct integration was used as the solution method. The time-dependent response of the structures was determined. Maximum response of the scaffolding was compared with results calculated according to the code recommendations.

Simulation of stochastic wind action on transmission power lines

The paper presents FEM analysis of the wind action on overhead transmission power lines. The wind action is based on a stochastic simulation of the wind field in several points of the structure and on the wind tunnel tests on aerodynamic coefficients of the single conductor consisting of three wires. In FEM calculations the section of the transmission power line composed of three spans is considered. Non-linear analysis with deadweight of the structure is performed first to obtain the deformed shape of conductors. Next, time-dependent wind forces are applied to respective points of conductors and non-linear dynamic analysis is carried out.

The choice of boundary conditions and mesh for scaffolding FEM model on the basis of natural vibrations measurements

Scaffolding is a specific construction with high susceptibility to low frequency vibrations. The numerical model of scaffolding presented in this paper contains real imperfections received from geodetic measurements of real construction. Boundary conditions were verified on the basis of measured free vibrations. A simulation of a man walking on penultimate working level as a dynamic load variable in time was made for verified model. The paper presents procedure for a choice of selected parameters of the scaffolding FEM model. The main aim of analysis is the best projection of the real construction and correct modeling of worker walking on the scaffolding. Different boundary conditions are considered, because of their impact on construction vibrations. Natural vibrations obtained from FEM calculations are compared with free vibrations measured during in-situ tests. Structure accelerations caused by walking human are then considered in this paper. Methodology of creating numerical models of scaffoldings and...

The relationship between wind pressure on the surface of rectangular prisms and atmospheric boundary layer parameters

The relationship between wind pressure on the surface of rectangular prisms and atmospheric boundary layer parameters

A comparative study of along-wind and crosswind responses of steel chimneys according to Polish and Eurocode standards

A comparative study of along-wind and crosswind responses of steel chimneys according to Polish and Eurocode standards