Geometrical imperfection, which is generally a result of manufacturing process and service conditions, plays a crucial role in load-bearing capacity of shell structures. This study presents a numerical study on knockdown factors of cylindrical shells as a result of torsional Mode-I type of geometric imperfections under compressive loads. The deformation patterns obtained from liner bifurcation analysis (LBA) for torsional Mode-I shape are used as a source of geometric imperfection. Then, geometrically nonlinear buckling analysis with imperfect model (GNIA) is incorporated with LBA in ANSYS Workbench to obtain limit loads of imperfect structures. A parametric study is thus performed to investigate the influence of imperfection depth on the load-bearing capacity considering a wide range of cylindrical shell configurations. Local and global buckling characteristics of the imperfect shells are examined and knockdown factors are characterized by three distinct regions as a basis of normalized imperfection depth. For a large number of shell configurations, a scattering of knockdown factors against normalized imperfection depth is given with mathematical expressions evolving lower and upper bounds. These expressions provide the minimum and maximum values of knockdown factors for a given imperfection depth, which can be treated as a design tool to ensure safety of the shell structure.
Axial compression Cylindrical shell Finite element method Geometric imperfection Knockdown factor
Birincil Dil | İngilizce |
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Konular | Makine Mühendisliği |
Bölüm | Research Articles |
Yazarlar | |
Yayımlanma Tarihi | 15 Aralık 2021 |
Gönderilme Tarihi | 5 Mart 2021 |
Kabul Tarihi | 1 Haziran 2021 |
Yayımlandığı Sayı | Yıl 2021 Cilt: 5 Sayı: 3 |