Modeling of hydrodynamic and kinematic processes during the operation of a mobile cargo rope complex

Abstract

Cargo aerial ropeways are an efficient mode of transport in mining industry. The purpose of the paper is to develop a method for modeling kinematic and hydrodynamic processes in the mechanisms of movement of carrying-pulling ropes equipped with hydraulic drives with frequency-throttle control at all stages of work such as acceleration of the transported load, steady motion and braking. The options of sequential installation (one-way and two-way) of adjustable throttles relative to the hydraulic motor are considered. The developed mathematical model provides computer modeling in time of the main characteristics of the hydraulic drive - the pressures and volumetric flow rates of the fluid at the characteristic points of the hydraulic system, as well as the kinematic and power parameters of the movement of carrying-pulling ropes (traveled distance, linear velocity and acceleration, required power, surmounted operating loads). For a specific option of mobile rope complex, the calculations of the indicated hydrodynamic, kinematic and force parameters are carried out and the obtained results are analyzed.

Optimal planning of the mobile cargo ropeway repair strategy

“…Determination of the limit (maximum) value [P] at which the condition ( 16) is met. To do this, it is convenient to use the approach [25]. It is based on determining the average probability of failure-free operation (P) av in a discrete number of points [P] 1 , …, [P] K within the possible change in the limit value [P] [[P] min ; 1.0) at [P] min in the range from 0.93 to 0.96 (Fig.…”

“…When performing calculations, it was assumed that during the service life T op , the time points of planned repairs  r,i are distributed evenly with frequency ΔT op = T op /N pr and all key structural elements have the same value [P m ] = [P] = const. The calculations were carried out in relation to a mobile ropeway with a length of 200 m with hydraulic frequency-throttle control of the speed of cargo movement [25] weighing up to 100 kN, formed by two self-propelled rope units with a height of the end tower of 12 m, with a standard service life of 40,000 hours. The values of the failure rate  m of key structural elements of transport units and the rope system were adopted on the basis of experimental and reference data [26][27][28].…”

Modeling the Reliability Indicators' Kinetics of a Mobile Ropeway Formed by the Self-Propelled Units

“…In any case, the calculation of technical risk is based on a quantitative assessment of probability of the emergency events occurrence, [16]. This requires development of computational methods for predicting changes in reliability indicators over time and, first of all, the probabilities of critical failures during the operation of the technical object under study, taking into account the specific features of its design and operating modes [10].…”

“…It is advisable to create mobile ropeways based on the self-propelled wheeled or tracked chassis with high load capacity and cross-country ability. At the same time, the main technological equipment (including mechanisms for spatial orientation and movement of carrying-traction ropes, supporting structures and the mechanism for their installation and fixation in the working position) is placed on the load-bearing frames of self-propelled units [10]. This approach allows one to get the greatest autonomy of the entire rope transport system.…”

“…A test evaluation of the program application [21] for reliability analysis was carried out in relation to a mobile ropeway with a length of 200 m, which has a hydraulic frequency-throttle control of the speed of cargo movement [10] weighing up to 100 kN. The ropeway is formed by the two self-propelled rope units with a height of the end tower of 10 m (Figure 1).…”