Digital shearography is a coherent optical method in conjunction with the digital image processing. It allows the shearogram, which depicts directly displacement derivatives, in real time to be observed and to be evaluated numerically. Strains are functions of the displacement derivatives. Thus, the shearogram contains the strain information, but usually it includes both the in-plane strain, e.g. ∂u/∂x, and the out-of-plane component, e.g. ∂w/∂x. In order to get the pure in-plane strain as well as the pure out-of-plane component, two linearly independent directions of illumination (usually the same but mutual and sequential illuminations) are introduced in the measuring device. The shearograms for each illuminating direction are evaluated by applying the phase shifting technique. The result by subtracting the phase maps of the two shearograms yields a new fringe pattern depicting the pure in-plane strain component and the result by adding the phase maps corresponds to the pure out-of-plane component. The theory and nondestructive tensile testing are demonstrated in this paper. Its applications for determining the strain distribution of the homogeneous and inhomogeneous material are presented.

In this paper the results of the experimental and theoretical analyses of angular frequency of the prerotating flow in the entrance pipe of turbomachines, at different operating regimes are given. The prerotation flow swirl appears far before the impeller blades entrance edge and it is the result of the developed circulation flows in the individual impeller channels that also has an affect on the impeller efficiency.
The mathematical model proposal for the angular flow frequency calculation in the entrance pipes of the model turbomachine (pump-turbine model) is given. The model is based on the determination of the relative circulation flow in the impeller channels that appears as a consequence of the effect of the rotated impeller channels.
The calculation results are compared by experimental data of measured prerotation flow angular frequency by simplified anemometer with six straight blades in the axial pipe direction. The anemometer is placed in the entrance pipe at distance of three-pipe diameters distance before the impeller entrance.

A research on vibration dampers efficiency, which was carried out at the Department of Mechanics of the Technical University of Ostrava is described in this paper. A cantilever beam was used as a test specimen. Its frequency response functions at the reference point were measured and natural frequencies, damping ratios and accelerances were evaluated on the test specimen without damper and with three types of dampers. The efficiency of vibration reduction of particular dampers was evaluated.

The paper summarises some results obtained at design of extensometrical transducers for indirect measurement of forces, namely at rolling stands and slab shears in conditions of heavy plates rolling mills. Two basic methods of experimental stress analysis were used at design and verification of properties of these transducers - planar two-dimensional photoelastic measuring and strain gauge method. We have performed simultaneously also indirect measurement of rolling forces on rolling stand roll housings.

A novel laser-based concept for monitoring settlements as well as inclinations of bridge piers over long periods of time is presented. Similar to the well known water leveling equipment the new system consists of several modules, which can be fixed and adjusted by simple means at the piers. Each module includes a laser source, optical components for beam forming and splitting and two position sensitive detectors. Two emitted and two incident horizontal beams in opposite directions ”interconnect” each module to its neighbors. Details are given about the mechanical and optical layout, the operational performance, especially with regard to influences of beam length and turbulent air. The uncertainty of results is investigated both by experiments and numerical simulation.