نوع مقاله : علمی - پژوهشی
نویسندگان
1 استادیار، مجتمع دانشگاهی مکانیک، دانشگاه صنعتی مالک اشتر، اصفهان، ایران
2 پژوهشگر، مجتمع دانشگاهی مکانیک، دانشگاه صنعتی مالک اشتر، اصفهان، ایران
3 کارشناس ارشد مهندسی هوافضا-سازه‌های هوایی، مجتمع دانشگاهی مکانیک، دانشگاه صنعتی مالک اشتر، اصفهان، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The use of cross spheres in the design and manufacturing of the pressure body of subsurface vessels has been of interest. In this article, stress and stability analysis of a Booth lemniscate shell of revolution under external pressure and various geometric imperfections is investigated. First, by introducing Booth Lemniscate shells, this widely used geometry is created without discontinuity and stress concentration. Stress analysis of these shells for different shape coefficients has been done using membrane stress theory. Using Python programming language and scripting in Abaqus software, the geometric equations related to the generating curve of shells with different shape coefficients were created and the stress field resulting from external pressure was calculated. By comparing the results obtained from the analytical solution and the finite element numerical solution, a proper match between the results is observed. Considering the importance of geometric shape defects in the post-buckling behavior of revolution shells, Booth lemniscate shells have been considered under the influence of various types of primary geometric shape defects, including axial and local symmetric ringing and shape defects resulting from the superposition of linear buckling modes. The reduction of the buckling strength of the shells has been investigated in the form of knockdown factor, and the highest impact was related to the shape defects resulting from the mode shape and the lowest was related to the local shape defects. The results show that the middle region of the shell is more sensitive to buckling, and the calculation of the knockdown factor shows that the critical load value decreases with the increase in the dimensions of the shape defect, and as the size of the shape defect increases, the slope of the knockdown factor graph decreases.
کلیدواژه‌ها [English]
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