Zbigniew Wójcicki

Analysis of failure conditions for a dynamically loaded composite floor system of an industrial building

Abstract Results of examination and analysis of cracks formation in a composite slab floor in an industrial warehouse hall is presented in the paper. During exploitation of the floor, on which lift trucks and presses worked, a lot of deep cracks occurred in the slab. In order to define characteristics of cracks and properties of concrete there were made different NDT examinations. Measurements of vibrations due to work of presses were also realized with aim to evaluate their possible influence on cracks formation. Static, dynamic and strength structural calculations were also made based on the model of continuous, multi-bay plate. They showed that applied slab reinforcement was sufficient and acting loads did not have to cause cracks. After 3D modelling of the building and taking into consideration the flexibility of main steel beams it was gained that in the RC floor slab over supports bending moments could occur nearly three times greater than calculated from the 2D model. Taking into consideration wron...

Nonlinearity identification of Jesus Christ the King monument on the basis of modal parameters

The work presents an attempt to identify the nonlinearity of the structure using a simple autonomous vibration recorder. The vibrations were measured continuously for 4 days in three directions, which easily made it possible to record various load states of the structure. The analysis of the response spectra shows a change in the eigenfrequencies caused by the level of load, which is a measure of the non-linearity of the structure. The presented method is an interesting alternative to expensive multichannel visit measurements, in which the equipment is compensated by the length of measurements