Project of GACR 101/95/0087 (1995-1997)

Methods of the optimization of dynamically stressed structures with required fatigue lives

Principal investigator:
Prof. Ing. Miroslav Balda, DrSc. (CDM)
Co-investigators:
Prof. Ing. Vladimír Zeman, DrSc. (ZČU)
Ing. Miloslav Kepka, CSc. (ŠKODA Výzkum Plzeň)

The project dealt with the problem of designing optimal structures fulfilling the guaranteed service life. A mathematical model of a structure was exposed to a characteristic excitation and its parameters were varied in order to get minimum weight of the structure while maintaining its guarantied fatigue life. The FEM model of the structure expressed the nominal stress state. The influence of concentrators was taken into account by the use of appropriate concentration factors. This approach enabled an optimal solution being found in an acceptable computing time even on personal computers.

Project of GACR 101/97/0226 (1997-1999)

A diagnostic equipment for monitoring rest fatigue life of machine parts vibrating extremely under rotation

Principal investigator:
Ing. František Vaněk, CSc.
Co-operator:
Prof. Ing. Miroslav Balda, DrSc. (CDM)

The title problem has been solved by another department. The deal of this Center is in developing original method of reconstruction of under-sampled signals of vibrating turbine blades, and in making proposal on the evaluation of the fatigue live of a blading. Simultaneously, the requirements for fatigue data of used materials have been posed for future estimating of residual service lives.

Project of GACR 101/99/0103 (1999-2001)

Fatigue of Machine Components Under Multiaxial Synchronized Loading with Phase Shift between Stress Components

Principal investigator:
Prof. Ing. František Plánička, CSc. (ZČU)
Co-investigator:
Prof. Ing. Miroslav Balda, DrSc. (CDM)

The goal of the project is to gain deeper and more accurate data concerning a mechanism of damaging steel machine parts in connection with results of an investigation on uniaxial stressing., and in context with the multiaxial fatigue research in the world. The experiments are running on the machine generating synchronized normal stress and torsional stress. The variable parameters are the ratio of both components and their phase shift. The criteria of the limit state will be formulated using experimental data from the vicinity of a concentrator.

Pilot project IT ASCR 10/4U (1998)

The influence of plasmatic coatings of the type TiN and WC-17Co on the fatigue of steel substrates

Principal investigator:
Doc. Ing. Jaroslav Kermes, CSc.
Cooperation:
Ing. Josef Kruncl

The project was devoted to an experimental research of the coatings TiN and WC-17%Co on the fatigue life of standard probes under harmonic loading. The goal of these tests was in obtaining data expressing an influence of the plasmatic coatings on the fatigue lives of the probes.

Pilot project IT ASCR 10/5U (1999)

A fatigue of structure steels with plasmatic coatings of the type TiN and WC-17%Co under stochastic loading

Principal investigator:
Doc. Ing. Jaroslav Kermes, CSc.
Cooperation:
Ing. Martin Václavík

The project worked out the problem of fatigue life of structure steels with two plasmatic sprayed coatings made out of WC with 17% Co and TiN. The loading was normal ergodic random narrow-band process with the characteristic frequency of 15 Hz and the factor of irregularity equal 0.7.

Pilot project IT ASCR 10/6U (2000)

Accreditation of Laboratory of fatigue damage

Principal investigator: Ing. Jaroslav Svoboda

The project conclude preparing works for the accreditation of the Laboratory of fatigue damage. The Laboratory have been accredited for realisation of fatigue testing metal and plastic specimens.

Pilot project IT ASCR 10/7U (2000)

Application of power spectral density for lifetime prediction of constructions subjected to wide-band random loading with Gauss distribution of amplitudes

Principal investigator: Ing. Jaroslav Svoboda

The goal of the project was to examine, whether there exists correlation power spectral density to fatigue lifetime of constructions subjected to dynamic loading. Tests of specimens of the material E460 have proven that the power spectral density influences the lifetime of constructions in the fields of propagation of short fatigue cracks.