Designing of ramps and modeling the stress-deformed state of steel framed construction
Students Name: Zhovtanetskyi Nazar Bohdanovych
Qualification Level: magister
Speciality: Robotics and Mechatronics
Institute: Institute of Mechanical Engineering and Transport
Mode of Study: full
Academic Year: 2023-2024 н.р.
Language of Defence: ukrainian
Abstract: The master’s qualification work considers the purpose and basic requirements for the installation of ramps, as well as the regulatory framework that defines them. A classification of ramps is proposed based on a review of real structures. Their design features and basic implementation requirements are defined. Based on the review, the purpose and main tasks of the scientific and practical research are determined. The purpose of the work is the design of collapsible ramps and the selection of rational parameters of the main structural elements. To achieve the goal, you need to solve the following tasks: - propose solutions for typical elements of ramps; - determination of operational and design loads; - assessment of the stress-strain state of the main structural elements of the ramp; - to offer some design variations of ramps for both exterior and interior spaces. The object of development and research is the design and calculation of a collapsible ramp. The subject of calculation and research is the characteristics of the stress-strain state. The second section presents the main structural elements used to implement the ramp. These include welded racks, crossbars, frames, decking, sidewalls, and handrails. The rack, crossbars and frames are made of profiled square tubes of different sizes in such a way that the frames and crossbars are strung on the racks with some small gap. This makes it possible to rotate the crossbars to implement inclined sections of the ramp. Fixation of frames and crossbars on racks is carried out using a bolted connection. The handrail is made of round pipes, brackets and connectors. Different handrails are used for different sections of the ramp, so they are made in advance both straight and curved, in particular for entering and exiting the ramp. Handrail for lower and upper levels. It is suggested to use a lattice floor for the ramp, which has a small mass and a high load capacity. The lattice decking is special and certified, and the dimensions are made to order for the respective ramp configurations. The fastening of the decking to the lintels and frames is ensured by special hooked threaded holders. Projects of two types of prefabricated ramps, external and internal, have been developed. The specifics of the implementation of the ramp for an indoor room with limited dimensions are shown. The peculiarity of the ramp is that it is suggested to use a vertical lift to compensate for the height, and the ramp is made in a straight line on the stairs. The proposed structures can be assembled quite quickly by 2 workers using a simple hand power tool, since all welding work and preparation of elements is carried out in the workshop. In the third section, the calculation of two schemes and load areas of the ramp is performed. A horizontal platform made of 4 racks and a frame, and a span made of 2 racks and a crossbar were considered. The platform is loaded by two people, and the span by one. Calculations of equivalent stresses and safety factors were performed for all nodes of the mentioned structures. The strength of the racks is provided with a margin of 2 or more, frames and jumpers 1.3, which is sufficient for welded structures and static load. The strength of bolted and welded joints is also tested and ensured. In the section of the economic assessment, a technical and economic justification of the proposed solution of a ramp with a vertical lift, compared to an inclined lift, is performed, the advantages of the proposed implementation and its industrial utility are given. Key words: ramp, metal structure, equivalent stresses, frame, calculation.