This paper deals with nonlinear mechanics of an elevator brake system subjected to uncertainties. A deterministic model that relates the braking force with uncertain parameters is deduced from mechanical equilibrium conditions. In order to take into account parameters variabilities, a parametric probabilistic approach is employed. In this stochastic formalism, the uncertain parameters are modeled as random variables, with distributions specified by the maximum entropy principle. The uncertainties are propagated by the Monte Carlo method, which provides a detailed statistical characterization of the response. This work still considers the optimum design of the brake system, formulating and solving nonlinear optimization problems, with and without the uncertainties effects.

Due to self-acting variability of operating conditions during the work of lifting devices, it is fundamental for the gears to stop the cabin at any clearance height. The operating conditions are changed by dust contamination influencing a proper braking process of the gear. This article presents...

Safety nets and safety nets are one of the best methods of collective protection during work at height. They are often used on construction sites, during renovations as an economical, convenient in transport protection against falls from a height of people or objects. They can replace heavy scaffolding (mesh working platforms) or railings (vertical and barrier nets). They take up less space and are less demanding when it comes to transport. The article presents the results of two attempts to dynamically drop the Hybrid III dummy onto jumping cushions, which are an alternative solution to the existing fall protection system with the use of safety nets. The analysis of the obtained results confirms that the jump cushions can be successfully used in protection against falls from a height, meeting requirements described in the relevant safety standards.

This article presents independent tests results focused on the geometry impact of progressive gear used in a short distance transportation devices on the braking distance length both under changeable operating conditions as well as changeable loading. Variable operating conditions were obtained...

Application of compact ropes made of area-contact wires in new types of hoisting installations operated at deep levels 1300 [m] and in smaller bucket hoists allows for reducing the drum size in the winder machine and the diameters of the rope pulley, thus prompting the optimization of their size and weight. Inspection of such ropes (BRIDON Dyform 34 LR, 18, 20, 25, 42 [mm] in diameter manufactured by Drumet) after an 8-years’ service by magnetic methods does not reveal any wearing and hence new diagnostic methods need to be developed or the existing ones improved. In consideration of stress concentrations, the working conditions of ropes needs to be determined whilst in service, particularly in tapered grips in rope attachments. This study summarises the diagnostic method employed to determine the working condition of ropes in tapered grips and describes the diagnostic equipment being currently developed, intended for inspection of rope condition in attachments.