### Contents of Journal of Mechanical Engineering *55,* 5 (2004)

HOSCHL, C.: Admissibility of mathematical models in the theory of
parametric vibrations of spur gears *(in Czech)* 251
ROBBE, M-F., CHRISTOPHE IMBERT, CH., LASSABATERE, T., CANY, F.:
Saturation process of a storage cell of a high-level radwaste
repository 259
KLIMAN, V., JAROSI, M.: System of continuous assessment of structure
fatigue reliability. Part II. Application – experiment *(in Slovak) * 293
KROPAC, O., MUCKA, P.: Estimation of road waviness using
the IRI algorithm 308

# Abstracts

### Admissibility of mathematical models in the theory of parametric vibrations
of spur gears

CYRIL HOSCHL

A simple system of gears with variable number of teeth in mesh was
studied by many authors. Mathematical models of such a system are necessarily
based on several simplifying assumptions. It may happen that the model violates
certain physical law. The author gives an example of such a model which was
unsatisfactorily discussed in the recently published literature. The sources of
the misapprehensions are clarified in the paper. The remedy lies in adding a new
inner non-tangential reaction which acts only at the moment of changing the
number of pairs of matching teeth, i.e., during the irregular edge contact of
teeth. This reaction forces the tooth of one gear to slide into the reduced gap
between the teeth of the other gear. Simultaneously, it transports the missing
energy into the system so that both the Newton's third law as well as the energy
conservation law are satisfied.

### Saturation process of a storage cell of a high-level radwaste repository

MARIE-FRANCE ROBBE, CHRISTOPHE IMBERT, THIERRY LASSABATERE, FRANCOIS CANY

In France, the concept of repository for high-level long-lived
radioactive waste is based on a set of underground galleries connected to
disposal cells containing waste canisters. Cells are filled with an engineered
barrier, and closed by a plug. The progressive hydration of the swelling clay of
both barrier and plug by the interstitial water seals the gaps, and provides a
global mechanical stability of the waste-clay barrier-plug-host rock system.
This paper is devoted to the analysis of the barrier and plug saturation by the
site water. Four configurations are examined. The evolution of pressure and
saturation is analysed and compared globally on the full geometry, and locally
along sections and at different points.

### System of continuous assessment of structure fatigue reliability. Part II.
Application – experiment

VLADIMIR KLIMAN, MARIAN JAROSI

Part II of the paper is devoted to the experimental verification of
the \linebreak methodology (proposed in Part I) of a continuous assessment of
the state of structure in view of fatigue damage. For the purpose of fatigue
damage monitoring the computer program has been elaborated which, on the base of
a continuous measurement of the loading process at critical locations of the
structure and inserted data on the material properties, enables to calculate and
display in real time all the characteristics needed to assess the
fatigue-reliability of the structure during its service. State of the structure
after a certain time of its operation is characterized mainly by the value of
remaining fatigue life and immediate probability of survival. Further parameters
enabling to assess reliability of operation of the structure from the point of
view of fatigue fracture occurrence are also monitored. The monitoring system
proposed has been verified experimentally on the base of comparison of the
theoretical and experimental function of survival probability of the test
specimens under loading by the s(*t*)
random loading process. A good agreement is proved. The factors influencing the
fatigue-reliability parameters, obtained by the monitoring system, are also
analysed.

### Estimation of road waviness using the IRI algorithm

OLDRICH KROPAC, PETER MUCKA

The waviness of the road unevenness can be estimated from two values
of the International Roughness Index (*IRI*) corresponding to two different
running speeds. Consequently, both direct and inverse conversion relations
between the *IRI* and parameters *C* and *w* of the power
spectral density (PSD) of the road unevenness are applicable.