This paper dwells upon securing solid cargo on a railcar. Transverse cargo shift and forces of elastic securing devices. The authors sought to calculate the shearing force acting on the elastic securing elements and retention bars; the retentive forces that prevent cargo from shifting across the car (the transverse shift); the transverse cargo shift; the force of elastic securing elements as exposed to transverse forces. This study relies on the second law as applicable to relative motion for a frictional constraint, as known in theoretical mechanics. The paper presents the calculated shearing and retentive forces. The authors calculated the equivalent stiffness of elastic securing elements. They thus computed the transverse shift (displacement) of cargo and the elongation of each elastic element that secures the cargo. They also found the forces of elastic securing elements as exposed to transverse forces. It was thus discovered that the forces of the second securing pair were more than double the acceptable limit, which would cause that pair to break during transport. To make the second elastic pair stronger, one might double the number of retention-bar fasteners so that the forces of the second fastening pair wouldn’t exceed the limits. An example of calculation is useful in developing a new methodology for calculating the elements of cargo securing on a car. The calculation results proved that to ensure guaranteed safety and reliability of the transportation process, it is necessary to either increase the number of securing elements of the retention bar, or increase the number of elastic securing elements with subsequent recalculation of forces in all elastic securing elements.
Cargo securing on a railway platform, elastic and retention fasteners, longitudinal transport force of inertia, forces in elastic fastenings. Purpose: The paper presents the calculation of the longitudinal transport force of inertia; determines the longitudinal force perceived by the elastic elements of the cargo securing; determines the reactions of retention bars depending on the number of bars and fasteners (nail); calculates the sum of all holding forces; calculates the forces in the elastic fasteners when exposed to longitudinal forces. Research methods: To determine the forces in the cargo securing devices, existing calculation methods are used. Moreover, the formulas of these techniques are presented in a form convenient for calculation. Main results: The paper proves that according to the existing method, the force in all elastic cargo fasteners under the influence of longitudinal forces has the same value, regardless of the different arrangement of the geometric parameters of the fasteners in space. The forces in them are more than 1.6 times higher than the permissible values. The calculations of forces in the elastic fasteners, which are performed by the specified method, are given. The results of the comparative analysis showed that the forces in all wire fasteners, in contrast to the existing calculation method, have different values. However, the strength of the second pair of wire fasteners of both one and the other direction is not ensured - the force in them more than two times exceeds the permissible value (61/24.8≈2.5), which will result in their destruction during the cargo transportation. Conclusions and their significance for the industry: Existing calculation methods do not provide guarantee strength of cargo fasteners. In the future, to calculate the fastening of cargo by shippers in the railway industry, a new calculation procedure should be applied for the allocation and fastening of cargo on the car.
This article explores issues related to the friction of the brake pads of a freight car. The coefficients of friction of composite and cast-iron pads of a new type, calculated for a range of different speeds, and the specific braking force during emergency braking are given. A sectional brake block for a freight car and a locomotive has been developed. The advantages of sectional brake pads have been scientifically substantiated. The obtained calculations allow us to recommend them for further study and implementation in operation on the railways.
Inaccuracy of the existing methodology for calculating cargo fastening. Cargo fastening by flexible and retention elements. The paper should define the “shearing” force across the car as the sum of the transverse transport inertia and wind load, taking into account the safety factor from tipping over; determine the transverse force perceived by the means of securing the load, taking into account the reaction of the retention bars of only one direction; calculate the forces in the elastic fasteners when exposed to shearing forces, taking into account the geometry of the fasteners according to existing methods. The research methods are based on the basic law of dynamics for the relative motion of a material point, where the transverse and vertical transferring inertia forces are formally assigned to external forces. The paper proves that according to the existing methodology, the force in all elastic cargo fasteners under the influence of transverse forces has the same value, regardless of the different arrangement of the geometric parameters of the fasteners in space. This is not true. The calculations of forces in the elastic fastening elements according to Appendix 8 of the existing methodology are given. Under the influence of transverse forces, the strength of the first and second pairs of elastic fasteners, both one and the other direction, are not provided by the method of Appendix 8 - the forces in the fasteners are greater than the permissible one (24.8 kN). Existing calculation methods do not ensure the strength of the cargo fastening elements.
Form a design (or dynamic) model on the basis of studying the physical model of a mechanical system (object); build mathematical models of cargo securing with inclined side surfaces of stop elements (bars) with simultaneous influence of longitudinal and lateral forces; perform a mathematical solution of the problem in the form of specific analytical formulas for calculating inclined stop bars as one of the cargo securing elements on the railway platform; make a specific example of the calculation of the forces acting on the cargo securing elements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.