Boštjan Harl

Probabilistic behaviour of joints on joint forces in mechanisms

This paper discusses the influence of the clearance in joints on the joint reaction forces in mechanisms. By using mathematical programming, the optimal parameters of kinematic chains can be efficiently obtained by using the deterministic approach. However, the situation becomes more sophisticated if random effects of tolerances of the arm lengths and the random pin positions have to be considered. In this work the influence of clearances on joint forces is calculated by using the Taylor approximation and the Monte Carlo method. The implementation of the model is illustrated with two examples. The first example considers a closed loop chain, representing a four-bar mechanism being an actual part of a hydraulic support, employed in mining industry. The second example considers joint reaction forces of car wiper mechanism.

Computer Supported Distribution And Assessment Of Homework Assignments In Mechanics

V prispevku je opisan nacin racunalnisko podprte izvedbe domacih nalog pri mehaniki z uporabo lastnega programskega paketa ASDN. Ta omogoca avtomaticno generiranje individualnih domacih nalog, njihovo distribucijo preko elektronske poste ter avtomatsko zbiranje in obdelavo rezultatov. Pozornost prispevka je usmerjena predvsem v delo ucitelja oziroma asistenta pri pripravi in razposiljanju nalog ter v delo studenta pri resevanju nalog in oddaji rezultatov preko spletnega vmesnika. Temu sledi kratek opis nasih dosedanjih izkusenj in nekaj zamisli za razvoj sistema ASDN v prihodnosti.