Certificate of Registration Media number Эл #ФС77-53688 of 17 April 2013. ISSN 2308-6033. DOI 10.18698/2308-6033
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Computational and experimental study of longitudinal stability of the thin-walled flat bar structure

Published: 24.03.2023

Authors: Egorov A.V., Egorov V.N.

Published in issue: #3(135)/2023

DOI: 10.18698/2308-6033-2023-3-2256

Category: Mechanics | Chapter: Mechanics of Deformable Solid Body

The paper studies longitudinal stability of the centrally compressed flexible flat bars using computational and experimental methods. Calculations were carried out according to the dynamic analysis methodology in the LS-DYNA software package. This methodology is based on three determining factors, i. e. volume, technological deviations and real-time mode. When constructing a hinged bar model, 3D finite elements, elastic-plastic material model, asymmetrical cuts of small volumes simulating geometric technological deviations were used. Critical forces determined by the methodology were compared with the Euler forces and with the experimental data. The experiment was carried out on bars with pointed ends, which were abutted against the angular technological equipment and provided with free rotation of the bar ends. As a result of the computational and experimental study of the flexible bars stability, it was established that in real bar designs there appeared initial shape imperfections noticeably affecting the critical forces magnitude, and the more flexible the bar was, the stronger this effect was. Quantitative relationship was also found between the experimentally measured critical forces and those calculated by the methodology and by the Euler formula. The issues of the origin of initial form imperfections in real bars were touched upon. Three possible directions for searching for a solution to the problem of bar stability using the methodology of dynamic analysis are shown depending on the method of introducing technological deviations into the structure calculation scheme. Diagrams of the hinged flat bars deformation during compression tests are provided.

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