PSI - Issue 36
A. Babii et al. / Procedia Structural Integrity 36 (2022) 203–210 A. Babii, T. Dovbush, N. Khomuk et al. / Structural Integrity Procedia 00 (2021) 000 – 000
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stress-and-strain state (SSS) taking into account real loading (Volkov et al. (1991), Eremenko (1991), Chernikov et al. (1998), Vyrskii (1990), Rybak (2003), Rybak et al. (1997)). In most cases external loads acting on the structural elements are time-dependent values. Thus, this factor should be taken into performing analytical research of SSS. This problem can be solved by the conventional methods of finding SSS of complex planar space loaded structural systems with considerable errors accepting a number of simplifications on which basis two problems can be solved. The first one is to determine external force factors, the second one is to determine internal force factors (Eremenko (1991), Chernikov et al. (1998)). The computer solution of such problems using the well known application program package (APP) where the calculation models are built by the finite element method (FEM) has been complicated by the specification ambiguity of the external variable load. It often results in errors at defining the internal force factors in metalwork’s . The advantages of FEM application in determining the SSS of bearing mechanical engineering metalwork’s in comparison with the traditional numerical methods are the following: simple algorithmization, possible full automation of equations writing and obtaining the results without any combined systems (Eremenko (1991)). SSS of frame structures by the finite element method comparing to the strain gauging has been studied in the paper (Vyrskii (1990)). The difference between calculations and research data is about 30 – 40%. 2. Problem statement and solution method The development of engineering methods of strength calculation and structural evaluation of agricultural machines supporting frames is one of the most important problems in their designing. The solution of such problems can be successfully achieved at proper level of the following factors implementation: determining the real dynamics of the loaded object; conducting experimental research under actual operating conditions of machines; statistical processing of the obtained digital material by maximal random of loading; specifying the SSS of structures by the experimental data; identifying the criteria of strength evaluation at few- and many cycle fatigue failure; obtaining the optimized structural parameters by the geometry of cross sections building and development of the basic diagrams with forecasted operational life (Chernikov et al. (1998), Rybak et al. (2005)). A number of the above-mentioned problems for certain design of agricultural machines or some of their elements (frames, sprayer booms sections and others) made of the rolled sections have been studied in the papers (Dovbush et al. (2014)). In this case the conducted theoretical and experimental research (Hevko et al. (2016), Hevko et al. (2018a), Trokhaniak et al. (2020), Vovk et al. (2019), Hevko et al. (2018b), Popovych et al. (2018), Okipnyi et al. (2020)) of root crops harvesters, different types of screw conveyors and their working tools has shown that it is necessary to conduct a series of investigations to determine the optimal parameters of bearing structural members. The increase of their strength assurance factor causes the increase of the material consumption of machines and working tools structure and further increased energy consumption to perform a technological process and other negative consequences. Here introduce the paper, and put a nomenclature if necessary, in a box with the same font size as the rest of the paper. The paragraphs continue from here and are only separated by headings, subheadings, images and formulae. The section headings are arranged by numbers, bold and 10 pt. Here follows further instructions for authors. 3. Determination of the load acting on the frame The base of agricultural machines including organic fertilizer applicators is a supporting frame where some joints, mechanisms and a body with a mechanism for fertilizer distribution are mounted. Some critical loads are taking place while a solid fertilizer loaded distributor is in operation and it is moving on the rough field surface with maximum translatory velocity causing fracture ( cracks formation) of the bearing frame structure which is shown on Figure 1. The study of fertilizer distribution and their kinematics on the distributor body space makes the stress state evaluation of a frame structure to substantiate the rational parameters of its sections.
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